What Is The Different Between % And Lel What Is The Different Between DTMF And FSK On A Cordless Telephone?

What is the different between DTMF and FSK on a Cordless Telephone? - what is the different between % and lel

I have something in the wireless specification: DTMF / FSK What is it? is that something to do Caller ID? What is the difference between DTMF or FSK --