The presence of the
display improves the usability of the phone. On the one hand, it is much more convenient to dial the desired number on such a device, since all numbers are displayed on the screen, which reduces the possibility of error. Also using the phone book feature is more convenient if there is a screen. On the other hand, the automatic number identification feature simply cannot be implemented on a phone without a display.
Hands-free mode allows you to have a conversation with the person on the other end of the wire, without picking up the phone for this and not looking up from other activities. For this, a speaker and a microphone built directly into the phone case are used.