Is one of message forms via the Internet; you only have to press the
icon or button on the site and the connection with the operator will follow
immediately. This function is often used on the websites for a quick
connection.
This is a way of communicating on the half-duplex communication line, includes receiving and transmitting devices (walkie-talkie) by the way of pressing the button for switching to the voice mode or transition to the listening mode. It works as a radio speaker; one can talk by pressing the button and can listen to a voice message by releasing the button.