Comparison Xiaomi Redmi 5a 16 GB / 2 GB vs Xiaomi Redmi 4a 16 GB

The term "operating system" refers to all types of firmware — both full-fledged OS like iOS and Android, used in smartphones, and software shells for regular phones (non-smartphones). The main difference between these two is that a full-fledged OS initially has more extensive features, and also allows you to install and remove various applications — from games and social network apps to specialized tools like photo and video editors.

Among modern smartphones, two operating systems are most widely used — Android and iOS. Here is a more detailed description of each of them:

— Android. Free open source OS from Google. Used by all modern manufacturers except Apple; presented in many versions — in particular, 10 Q, 10 Go Edition, 11 R, 11 Go Edition, Android 12, Android 12 Go Edition, Android 13, Android 13 Go Edition, Android 14, Android 14 Go Edition, Android 15 are relevant today. This OS is notable primarily for its full-fledged multitasking and an extensive range of available applications — Android surpasses iOS in both;...on the other hand, in general, the quality of Android applications is somewhat lower due to the low requirements for them. Initially, Android has tight integration with Google services — the Google Play app and content store, Gmail mail, Google Drive cloud storage, etc.; however, exceptions to this rule are possible. Note that the latest versions of this OS can be found on the market both in its original form and in one of two specific editions:

• - Go edition. Modification of Android, designed for low-cost smartphones with "weak" hardware. Both the OS itself and standard applications (Assistant, Gmail, etc.) have been redesigned in this edition in such a way as to ensure reliable operation even with low performance. At the same time, the developers tried to preserve the features of full-fledged Android as much as possible — however, some specific fwatures in the Go Edition were still not available (for example, standard maps do not support turn-by-turn navigation, and compatibility with Wear OS on smartwatches is not provided).
• - HMS. Edition of Android, used in smartphones from Huawei. Due to US sanctions against China, this company cannot fully cooperate with Google — in particular, use Google services (Google Mobile Services — GMS) in its Android smartphones. As a replacement, HMS — Huawei Mobile Services were introduced. These services include Huawei ID, AppGallery, equivalents of Google's core services (assistant, browser, cloud storage, music/video, etc.), and app developer tools.

As for individual versions of Android, here are the main features of the options that are relevant nowadays:

• - Android 10. Version released in September 2019. This version introduced an expanded set of full-screen gestures (with the possibility of optimization in individual applications — in particular, disabling gestures on certain areas of the screen to avoid conflicts), a "dark" screen mode at the system level, a number of important security updates (including a separate encryption standard for weak devices that do not support the AES format at the hardware level), full support for 5G communications and improved capabilities for working with augmented reality. In addition, a number of solutions have been implemented to optimize the experience on foldable smartphones with a flexible screen.
• - Android 11. Another major update, released in the fall of 2020. The main updates touched messages and notifications. So, a separate section "Conversations" for messages was created in notifications, it also became possible to display various correspondence in the form of a "bubble" on top of any running application (Bubbles feature). Do Not Disturb mode has been expanded — now you can add exceptions to it for individual correspondence. Other important innovations include a system tool for recording screen video, a single control centre for smart home components, quick switching between playback devices (phone speaker, wireless headphones, Smart TV, etc.), native support for Android Auto, as well as expanded the ability to control the access of individual applications to certain data.
• - Android 12. A popular operating system released in 2021. The new concept of Material You is based on discreet colour palettes and minimalistic two-dimensional objects with advanced animation. The system theme now adapts to the colour scheme of user's desktop wallpaper (Monet feature), and instead of round settings icons in the notification bar, rectangular dice with rounded edges are now used. The designers also reworked the animation of flipping through desktops, plugging in a charger, and so on. In smartphones running Android 12, instead of precise geolocation, you can select approximate location information, and icons have appeared in the notification bar that signal the inclusion of a camera or microphone when using certain applications. The Privacy Dashboard option reveals information about which programs have accessed the camera and microphone. The NFC on mobile devices can henceforth be used as a virtual key for a car (Car Key). Another innovation in the system is the call to Google Assistant by long pressing the power button of the smartphone.
• -Android 13. A popular operating system for mobile devices, the 13th version of which was released in 2022. There were no major innovations in Android 13, but the OS brought a number of useful features and changes. In particular, the Material You workspace design concept can now pick primary colors from installed wallpapers or themes and apply them to the display of icons throughout the system. Privacy of user data has been taken to a new level of quality - in Android 13, you can configure individual permissions and select specific images from the Gallery that the application is granted access to. For each program, the user is free to choose a standard interface language. The system has also become more energy efficient, with improvements to the clipboard and barcode scanner.
• -Android 13 Go. A light version of the Android 13 operating system, designed for installation on low-powered smartphones. A distinctive feature of the OS is the presence of a special algorithm that optimizes the computing power of the smartphone. Also, the system lacks some hardware-demanding functions. Android 13 Go introduced the design concept of the Material You interface, which allows you to adapt the color scheme of the menu to match the installed wallpaper. From the full-fledged Android 13 system, the Go version borrowed the function of issuing permissions to applications to send notifications and the ability to change the language for specific programs.
• - Android 14. Operating system for mobile devices, released in 2023. There are, frankly, few system changes in the 14th version of the Android OS, and its main emphasis is on flexible customization of the interface. Among the innovations, it is important to mention the function of displaying notifications using the flash or display: for each application, you can now set a flashlight blinking pattern, and in the case of the screen, select the color palette of notifications. Also in the operating system, we implemented a useful ability to adjust the capture of screenshots, added a widget to display the battery charge and a list of active connections, and introduced an option for cloning applications in a systemic way. System fonts in the OS can be enlarged up to 200% of the standard size, while the scaling is implemented non-linearly - first of all, it is used for small text. Among other things, there are improved energy efficiency of the system and cosmetic changes in the interface in the manner of more rounded elements.
• - Android 14 Go. A streamlined version of Android 14 for budget smartphones with limited hardware resources. The Go Edition distribution includes simplified standard apps while providing basic Android functionality with minimal impact on performance and energy consumption. Despite its "lightweight" nature, Android 14 Go supports enhanced notifications, new controls, and privacy settings that debuted in the full 14th edition of Google’s OS. However, smartphones running the Go version are not compatible with Wear OS smartwatches — a point to consider.
• - Android 15. Android 15 was released in 2024. Notable new features include native support for satellite communication (for contacting emergency services or sending SOS signals), the ability to record and share only a specific app window (rather than the entire screen), updated hardware extensions for camera control, expanded message management, and flexible volume control. The system also includes traditional improvements in security features and enhanced energy efficiency.

— iOS. Apple's own operating system, used only in the gadgets of this manufacturer. The main advantages of iOS over Android are, first of all, careful optimization for specific devices (which allows you to achieve good performance with relatively modest amounts of RAM), general usability and safety, as well as high quality applications. In addition, iOS updates are released regularly and are available for all devices (with the exception of frankly outdated ones that no longer can handle new versions of the system). On the other hand, this OS does not support multitasking and is as closed to the user as possible: in particular, applications can only be installed from the original store, there is no access to the file system, memory cards are not supported.

— HarmonyOS. Huawei's Universal Operating System, also known as Hongmeng. It is used in a wide range of devices: appliances from the smart home ecosystem, smartwatches, smartphones and tablets. Harmony OS is a kind of add-on on top of Android without Google services. The app store for Harmony OS devices is called AppGallery.

— FlymeOS. A modified version of the Android operating system used as a software shell for Meizu smartphones. The OneMind engine is responsible for the stability of the OS. There is no application menu in Flyme OS, and all program icons are scattered across desktops. Distinctive features of the shell include advanced tools for working with files, the Aicy voice assistant, flexible adjustment of the mEngine vibration signal, Family Guardian parental control options, a structured gallery with a convenient visual editor.

— Proprietary. This term most often means the basic firmware installed in a regular phone (not a smartphone), usually, a push-button one. Such firmware has a more modest set of pre-installed programs than full-fledged OS; expanding this set is at best possible with Java-based universal mobile applications, and often additional applications are not supported at all. However, this cannot be called a disadvantage due to the specifics of the use of traditional phones.

Note that you can find devices with other operating systems, in addition to those described above. However, for the most part, these are either outdated models or devices with rare and uncommon types of firmware.

The most popular nowadays are chips from Qualcomm and MediaTek, CPUs from Unisoc are slightly less common. Qualcomm has several processors of each series, namely Snapdragon 778G, Snapdragon 7 Gen 1, Snapdragon 7+ Gen 2, Snapdragon 7s Gen 2, Snapdragon 7 Gen 3, Snapdragon 7+ Gen 3, Snapdragon 865, Snapdragon 870, Snapdragon 888, Snapdragon 8 Gen 1, Snapdragon 8+ Gen 1, Snapdragon 8 Gen 2, Snapdragon 8 Gen 3, Snapdragon 8s Gen 3. And Mediatek has a low cost series MediaTek Helio P and a line of advanced chipsets MediaTek Dimensity (Dimensity 1000, Dimensity 7000, Dimensity 8000, Dimensity 9000).

Knowing the name of the CPU model installed in the smartphone, you can find detailed data on a particula...r CPU and evaluate its level and general capabilities. This is especially true in light of the fact that these capabilities depend not only on the number of cores and clock speed, but also on the specific nuances of the design.

The test results are specified either by a younger model in a line or a particular model, made for a better understanding performance of phone models if you compare phones against these parameters. For example, the 128 GB model has test results, and the 256 GB model has no information on the network, and in both models you will see the same value that will give an understanding of the overall performance of the device. But if the editorial office has information for each model individually, then each model will have its test results filled out, and the model with bigger RAM will have bigger values.

The result shown by a device when undergoing a performance test (benchmark) in Geekbench.

Geekbench is a specialized benchmark designed for processors. Since version 4.0, it also includes tests for graphics processors, and by the end of 2019, version 5 of the benchmark was released. Typically, the specifications for portable gadgets include data specifically for the CPU. During testing, Geekbench simulates workloads that occur during real-world tasks, evaluating both single-core performance and the efficiency of multi-core operations. This provides a solid overview of the processor's capabilities in everyday use. Additionally, Geekbench is cross-platform, allowing for comparisons between the CPUs of different devices (smartphones, tablets, laptops, PCs). In reference materials, only the multi-core test results for the processor are usually provided.

Aperture of the main lens of the front camera installed in the phone. For models with several lenses (see "Front camera" — "Number of lenses"), the main one is the lens which is responsible for the main part of the shooting and does not have a pronounced specialization (auxiliary, ultra-wide-angle, etc.).

This parameter is indicated by a fraction, for example f/1.7; the smaller the number in denominator, the higher the aperture ratio, the more light the lens is able to transmit. Theoretically, a better aperture improves low-light performance, reduces motion blur, and can be useful for creating beautiful background blur; however, in fact, looking for a fast front camera(f/1.9 and better) makes sense mainly in cases where you plan to take selfies often and in large quantities and want to achieve the maximum quality of such pictures.

Communication standards supported by the mobile phone. In the modern world, several standards related to different generations are actively used: GSM, 3G, 4G (LTE), 5G (including fast mobile internet), CDMA. They vary in both specs and prevalence in different countries:

— GSM. The earliest of the communication standards found in modern telephones. Belongs to the second generation (2G). Allows you to make voice calls with acceptable sound quality, as well as transfer data at speeds up to 474 Kbps (using EDGE technology). Nowadays, GSM is considered completely obsolete, it has been almost universally replaced by more advanced standards of the next generations (3G, 4G, etc.). However, 2G support is found in most modern devices — not so much because of practical necessity, but because of technical features. The fact is that almost all communication standards that are relevant nowadays are add-ons over GSM, and modules for working with these standards are almost guaranteed to be compatible with GSM as well.

— 3G. In a broad sense, the 3G category (third generation communications) includes several standards. However, in the east european mobile phone market, this term refers specifically to the connection of the UMTS format. This standard is a development of GSM, such networks are often deployed on the basis of ready-made networks of the 2nd generation and c...an also serve GSM phones without problems. Specifically, UMTS provides data transfer rates from 2 to 70 Mbps, depending on additional technologies implemented by a particular operator. This is already comparable to fixed Internet access; so, despite the spread of newer standards, 3G communication and phones for it are still quite popular — especially since such devices are compatible with 4G and 5G networks.

— 4G (LTE). Communication 4 generations based on the LTE standard; other 4G standards are not used in mobile phones. LTE is a further development of 3G (UMTS), deployed on the basis of the same technical base, but operates at higher speeds — up to 173 Mbps, which is comparable to a full-fledged broadband Internet connection. LTE networks are commercially operated in many countries of the world, but not in all; therefore, before buying a 4G-compatible phone, it's a good idea to check if it will be possible to use all its features in your area.

— 5G. Further, after 4G, the development of mobile communication standards. In the official specifications of this generation, a peak speed of 20 Gbps for reception and 10 Gbps for transmission, guaranteed speed (at high network load) of 100 and 50 Mb/s, respectively, as well as a number of solutions aimed at improving reliability and overall connection quality. A set of such solutions includes, in particular, multi-element antenna arrays (Massive MIMO) and beamforming technologies (Beamforming) at base stations, as well as the possibility of direct communication between subscriber devices. With all this, this standard allows to reduce energy consumption in comparison with its predecessors.
Separately, it is worth mentioning the rumors about the dangers of 5G communications for health. According to modern scientific data, such a connection does not pose a danger to the human body, and the rumors mentioned are conspiracy theories that are not supported by any weighty arguments.

— CDMA. CDMA networks are known to users primarily by the activities of cell phone networks that provide the opportunity to receive a mobile phone with a direct city number. At one time, these networks competed with GSM and more advanced standards based on it, but as mobile communications developed and became cheaper, CDMA operators for the most part curtailed their activities in the voice communications market and switched to mobile Internet access services. It is worth noting here that the EV-DO Rev.A and Rev.B data transmission technologies available in CDMA networks are capable of providing connection speeds at the level of third-generation networks (up to 3.1 Mbps in the first case and up to 14.7 Mbps in the second), so in some places these services were promoted under the 3G label. However, this connection should not be confused with UMTS-based 3G (see above) — these are two fundamentally different standards that are incompatible with each other. Roughly speaking, if we are talking about 3G in a mobile phone, usually, we mean UMTS, but 3G modems more often use CDMA (EV-DO).

It is worth noting that the GSM, 3G and 4G standards (in that order) are, in fact, stages in the development of mobile networks of the same type. In fact, this means that a phone with support for a later standard, by definition, supports earlier ones — for example, a device with LTE is able to work with both GSM and 3G.

You also need to remember that different ranges can be used within the same standard, and not all of them can be supported in a mobile device. However phones officially sold in a certain country are usually optimized for local networks, and there should be no problems with them. But if the device is planned to be imported from another country, and it was not intended for the local market, it makes sense to first clarify the compatibility by bands. Otherwise, a situation may arise when the device simply “does not see” the network, although formally it will be compatible with a certain communication standard.

The quantity and types of removable cards (SIM, memory cards) that can be installed in the phone. On E-Catalog this parameter is specified only for devices that allow the installation of more than one SIM card — most often that means 2 SIM cards, however, you can find devices with three or even four corresponding slots.

Initially several slots mean that several phone numbers can be used on one device. Thus it is possible to combine personal and work numbers, separate plans for calls and the Internet, etc. in one device. However modern devices (especially smartphones) often provide the combined design “SIM + SIM / memory card " : one of the slots is intended only for SIM, the second can be used both for a SIM card or for a memory card such as microSD or Nano Memory (see "Memory card slot"). At the same time, there is no separate slot for a memory card in the device, so the user has to choose between the second number and additional storage. Therefore, if you want to use 2 SIM cards and a memory card at the same time, you should pay attention to models where this is directly stated.

It is also worth considering that individual slots may differ in the type of compatible SIM cards; see below for details.

Inputs and outputs of the smartphone.

This paragraph usually specifies the type of charging and data port (most often it's USB-C), and whether the smartphone has a mini-jack (3.5 mm)(there are devices without it). It can also indicate the interface of the USB-C port up to the high-speed third version ( USB-C v 3), the location of the 3.5 mm jack (headphone output) and additional ports for a more specific purpose.

The main ports are used primarily for charging the battery, for connecting various accessories to the phone and for connecting the device itself to the computer via a cable. 3.5 mm port (mini-Jack) is intended primarily for headphones and other audio accessories, although other usage formats are possible. Here is a more detailed description of the different types of connectors:

— USB-C. A relatively new type of universal interface, a kind of successor to microUSB, which is increasingly used in mobile devices. USB-C differs from its predecessor primarily in slightly larger dimensions and a convenient two-sided design: thanks to it, it does not matter which side to insert the plug. In addition, this interface allows you to implement more advanced functions than microUSB — in particular, certain fast charging technologies were originally created specifically for USB-C. USB standard supported by this ty...pe of connector can be specified separately. Today the options are:

• USB-C 3.2 gen1. The standard formerly known as USB 3.0 and USB 3.1 gen1. Provides data transfer rates up to 4.8 Gbps.
• USB-C 3.2 gen2. The current name for the standard, formerly USB 3.1, then USB 3.1 gen2. The connection speed on this interface can reach 10 Gbps.
• USB-C 3.2 gen2x2. A standard (formerly known as USB 3.2) that delivers twice the speed of "regular" USB 3.2 gen2, up to 20Gbps. Unlike previous versions, it was created specifically for the USB-C connector.

— microUSB. A universal connector, which formerly was extremely widely used in portable devices (with the exception of Apple devices). It is less convenient and technically advanced than USB-C, therefore it is gradually losing popularity; however, there are still quite a few devices with microUSB out there.

— Lightning. Apple's proprietary connector used exclusively in the iPhone. It has a double-sided design that allows you to connect the plug in either direction. In modern iPhones, it is used both as a universal one and for connecting headphones (in 2016, Apple abandoned the 3.5 mm audio output in their smartphones).

— Original port. The one that does not belong to the types described above. Nowadays, such solutions are extremely rare — standard interfaces are more convenient and versatile, as they allow you to use not only "native" accessories, but also solutions from third-party manufacturers.

— USB A. Full-size USB port — similar to those used in PCs and laptops for connecting various peripherals. It has a similar purpose in phones, it is mainly used for flash drives and other external accessories (the specific set of supported devices should be specified separately). Usually, it is supplemented with a more traditional universal connector like microUSB or USB-C; in general, for a number of reasons, it is very rare.

— Magnetic connector. A connector that uses a permanent magnet instead of a standard plug system to hold the cable. Such solutions are used mainly in devices with water protection (see "Waterproof"), and most often — to charge the battery in addition to standard universal connectors (usually microUSB or USB-C). The main convenience of the magnetic connector is that it does not need plugs to protect it from water. It simplifies the connection and disconnection of the charger, and secondly, the wear of the plugs on standard ports is minimized — they do not need to be opened and closed every time you charge the smartphone. However only a special “native” cable is suitable for a magnetic connector; but if this cable is lost or broken, it may be possible to charge in the usual way, through a traditional universal connector.

— Mods contacts. Contacts for connecting special additional modules that expand the functionality of the device. Such equipment is usually found in some rugged phones. The modules themselves are usually a kind of "cases" that are put on the back of a smartphone; in such a “case” there may be, for example, an additional battery, a gamepad or even a thermal vision mod.

— Mini-jack (3.5 mm). A connector primarily used to connect wired headphones and other audio devices (such as portable wired speakers). Such a connection is extremely popular among audio accessories (and not only for "mobile" purposes); so finding headphones, a headset or speakers for this connector is usually not a problem. In addition, the 3.5 mm jack can also be used for more specific tasks — for example, connecting a selfie stick, a card reader or exchanging data with wearable fitness sensors and other specific equipment. However, such features are rarely used and require the installation of special applications, but connecting headphones is the initial function of such a connector, available by default. So the mini-jack connector is often called the "headphone output".

— Location of the headphone output. The 3.5 mm output described above in modern phones can be located on the top, bottom or side of the device. However, the latter option is generally less convenient than the first two, and therefore is rare. And the choice for this indicator depends primarily on how exactly you are going to carry the phone and which side will be used to connect headphones to it; For different situations, the options will also be different.

Additional features and capabilities of the device.

In modern mobile phones (especially smartphones) a very extensive amount of additional features can be provided. These can be both already familiar features, many of which are directly related to the original purpose of the device, as well as fairly new and/or unusual ones. The first category includes an emergency call button(often found on phones for the elderly), noise cancellation, FM receiver, notification light and a light sensor. The second category includes a face and fingerprint scanner (the latter can be located on the back cover, side panel, front and even right under the screen), gyroscope, advanced full-fledged flashlight, stereo sound, 3D surround sound, Hi-Res Audio and even such exotics as a barometer. Here is a more detailed description of each of these options:

— 3D face scanner. A special...technology for recognizing the user's face — not just by photographing, but by building a three-dimensional model of the face based on data from a special module on the front panel. This technology is constantly being improved, nowadays it is able to take into account the change of hairstyles and facial hair, the presence of glasses, makeup, etc. At the same time, the recognition of twins and children's faces still remains weak points (they have fewer individual features than adults ). The main use of a face scanner is authentication when unlocking a smartphone, entering applications, making payments, etc. At the same time, other, more original use cases are possible. For example, in some applications, the face scanner reads the user's facial expressions, and then this facial expression is repeated by an emoji on the phone screen.

— Fingerprint scanner. Fingerprint reader. It is mainly used for user authorization - for example, when unlocking the device, entering certain applications or accounts, confirming payments, etc. As for placement options, fingerprint scanners are increasingly moving from the back cover of the device to the surface of the side power / unlock button - to You can touch the sensor on the side with your thumb without releasing the smartphone from your hands and practically without changing your grip. Some time ago, sensors on the front of the case were quite popular - in particular, thanks to Apple, which was the first to tightly implement fingerprint recognition in its gadgets. However, such placement inevitably increases the size of the bottom frame, so the front fingerprint scanner is rare in modern smartphones. A good alternative to it is scanners right on the screen (more precisely, under the display matrix), which do not take up extra space on the front panel.

— Stereo sound. The ability to play full stereo sound through your phone's own speakers, without external audio devices. There must be at least two speakers for this task. This complicates the design and increases its cost, but it has a positive effect on the sound quality: the sound is more expressive and detailed than when using a single speaker, it has a volume effect, as well as a higher volume.

– 3D surround sound. The mechanics of spatial surround sound with localization of sound sources in three-dimensional space allows you to deeply immerse yourself in the atmosphere of films, enjoy listening to audio tracks, or completely immerse yourself in mobile gameplay. Algorithms for implementing 3D sound in smartphones differ in terms of software and hardware support, but they are all aimed at achieving the effect of realistic sound stage. Note that support for 3D surround sound can mean both commonly used technologies such as Dolby Atmos or DTS:X Ultra, as well as proprietary solutions from individual audio brands that have a hand in the sound subsystem of a mobile device (AKG, JBL, Harman, Huawei / Honor Histen, etc.).

– Hi-Res Audio. Mobile device support for high-resolution audio Hi-Res Audio - a digital signal with parameters from 96 kHz / 24 bits. Audio tracks in this format sound as close as possible to the original ideas of the authors of the compositions. The result is a sound that is as close as possible to what was recorded in the studio.

— FM receiver. Built-in module for receiving radio stations broadcasting in the FM band. Some devices also support other bands, but FM is the most popular nowadays (due to the ability to transmit stereo sound), it is in it that music radio stations usually broadcast. Note that some devices for reliable reception may require the connection of wired headphones — their cable plays the role of an external antenna.

— Notification indicator. Physically separate light beacon, pulsating or being constantly lighted up in response to incoming notifications of missed calls and received messages (including the ones from instant messengers and social network clients). Also, the indicator light usually signals a low remaining battery level and lights up during the battery recharging. The implementation of the notification indicator can be different: for some phones it is single-colour, for others it has colour coding of signals, flexibly adjustable for certain events through the settings menu. The light beacon allows you to visually comprehend the presence of incoming notifications without having to turn on the smartphone screen.

— Emergency call button. A separate button designed for use in critical situations. The specific features of such a button may be different, depending on the model: sending “alarming” SMS to selected numbers, automatically receiving calls from these numbers or calling them in turn, turning on the siren, etc. Anyway, the “emergency” button is usually clearly visible, and its presence is especially useful if the phone is used by an elderly person (in fact, in specialized devices designed for elderly, this button is almost mandatory).

— Noise suppression. An electronic filter that cleans the user's voice from extraneous noise (sounds of the street, the rumble of the wind in the microphone grille, etc.). Thus, the person at the other end of the line hears only the voice, with virtually no extra sounds. Of course, no noise reduction system is perfect; however, in most cases, this feature significantly improves the quality of the speech transmitted by the phone to the other person.

— Gyroscope. A device that tracks the rotation of a mobile phone in space. Modern gyroscopes, usually, work on all three axes and are able to recognize both the angle and the rate of turn; in addition, this feature almost necessarily means the presence of an accelerometer, which allows (among other things) to detect tremors and sharp movements of the device.

— Full-fledged flashlight. The presence of an advanced flashlight in the phone — more powerful than the usual one. The specific design and capabilities of such a flashlight may be different. So, in some devices, a separate LED (or a set of LEDs) is provided on the upper end, and this light source is used only as a flashlight. In others (mainly smartphones), we are talking about a special design of the flash: it consists of several LEDs, and only a part of them is usually used to illuminate when shooting, and all at once to work in flashlight mode. And the additional features of such a light source may include a laser pointer, beam focus, brightness control, etc. Anyway, most models with this feature are rugged devices with increased resistance to dust, moisture and shock (however, there are exceptions).

— Light sensor. A sensor that monitors the level of ambient light. It is mainly used to automatically adjust the brightness of the screen: in bright ambient light, it increases so that the image remains visible, and in twilight and darkness it decreases, which saves battery power and reduces eye fatigue.

— Barometer. Sensor for measuring atmospheric pressure. By itself, the barometer only determines this pressure at the current time, but the methods of using such data may be different, depending on the software installed on the phone. For example, some navigation applications can determine the elevation difference between individual points on the ground by the difference in atmospheric pressure at these points; and in weather programs, barometer data can improve the accuracy of weather forecasts. Also, this feature will be useful for weather-sensitive people: it signals a change in the weather, allowing you to more accurately determine the cause of ailments and take measures to eliminate them.