Call waiting with “Caller ID” uses a special signal in
order to warn you about an incoming call, during another call there are shown the
name and number of the calling subscriber on the display. The function also
allows switching between two calls.
Desk phones, mainly it is a wire telephone placed on the table. There
are very many variations of such telephones differentiating with the quality of
sound and connection as well as with the pack of functions and price.