Button control
The presence of a touch screen allows you to configure and control the device using the display. However, for greater convenience, in many e-books, regardless of the type of screen, the
buttons still act as the main controls. Firstly, they can be pressed with gloves or wet hands. Secondly, holding a book with two hands is much easier to press the button to turn the page than to swipe your finger across the screen.
E-book formats
File formats supported by the reader that contain text (and sometimes graphic information). The most popular in the CIS are, in particular,
FB2,
TXT,
HTML,
WORD (DOC),
RTF,
ePUB,
Djvu and
PDF.
Photo/video formats
File formats supported by the reader that contain multimedia information — graphics or video. The most popular image file formats are, among others,
JPG(the standard format for modern digital photography), BMP and GIF; video files —
MP4, MPG,
AVI, 3GP (video format for mobile devices),
FLV, MOV.
Other formats
Many advanced reader models are able to "perceive" not only e-books, graphic files and videos, but also other file formats. The most common support for music files:
MP3, WMA, in especially advanced cases —
AAC, OGG, lossless formats APE and
FLAC. Of the non-musical formats, some readers support
ZIP and RAR archive files, as well as Microsoft Office documents (PPT(X), XLS(X))
Operating system
A software product that ensures the correct operation of the installed software and convenient management of e-book functions. Conventionally, the family of "readers" is divided into two large camps: some work under the Android OS (in various versions of
Android 6.0,
Android 9.0,
Android 10,
Android 11,
Android 12), others run Linux. The Android system is not always well adapted to the features of the e-book interface, but a significant trump card up its sleeve is support for installing applications from the Google store.
Linux -led readers stay afloat longer in offline mode, but most of them cannot be installed with third-party applications.
CPU speed
The frequency of the built-in e-book processor is one of the main indicators that determine its performance (the speed of copying files to the built-in memory, opening larger files, loading Internet pages, etc.). On the other hand, this indicator is not decisive and can only be used for comparison in books of the same model range.
RAM
The amount of the reader's own RAM, that is, the memory used for temporary data storage during operation. The speed of the e-book directly depends on the amount of RAM, especially when working with large files. So the average value can be considered
RAM 1 GB and
2 GB, and more advanced models have
3 GB,
4 GB and even
6 GB of memory.
Storage capacity
The amount of the reader's own built-in memory, i.e. the memory used for persistent data storage. The more memory, the more content can be stored at a time in the e-book. At the same time, note that even the largest text (TXT, FB2, HTML) files, usually, rarely exceed 2 – 3 MB, so relatively little memory is needed for storage. Graphic and audio files, in turn, are more voluminous, but most of the space is needed for video files. Therefore, depending on the use of the gadget, you will need a different volume, whether it be
4 GB, 8 GB or more. Many readers support the ability to expand their own memory through removable cards (see
Memory card slot).
Card reader
Possibility of expansion of own built-in memory at the expense of replaceable memory cards. In addition to increasing the amount of memory, such a medium facilitates the exchange of information between an e-book and other devices: for example, you can download a book to a laptop equipped with a card reader, write it to a memory card and install the card in an e-book. Note that at the present time several types of memory cards are actively used, and not all of them are mutually compatible; therefore, when buying a book with a memory card slot, you need to pay special attention to the type of cards supported.