Analogue walkie-talkie radios have been around since the 1940s - although they have improved and got a lot smaller, lighter and have longer-lasting batteries than the early models.
But the basic method of operation has remained the same. The user's voice is transmitted as an analogue waveform to the receiving radio.
A digital radio is one that digitises the user's voice and transmits it as a stream of bits. The receiving digital walkie-talkie then converts this back into an audio voice signal.
Because the signal is digitised, digital error correction will result in a clearer voice coming out of the receiving radio. Some digital radios can also screen out "background noise" which further enhances the quality of the voice being transmitted.
Digital radios do, however, tend to have a fraction of a second delay due the time taken to digitize, send and decode the transmitted voice.
Many digital radios can offer new functionality such as GPS tracking, complex call groups, individual calling etc.
It is a lot harder for third parties to "eavesdrop" on digital radio signals than it is with unencrypted analogue radio signals.
Because digital radios are a new product and because they are more complex devices to make, they tend to cost quite a lot more than many analogue walkie-talkies.
