Re: what is difference between tone dialing and pulse dialing?

Pulse dialling sends the dialled numbers by briefly interrupting the line 
current once for each number (twice for 2, three times for 3 etc.). This 
was the original dialing method used with the old electromechanical 
(Strowager) exchange equipment and mechanical telephone dials.

Tone dialling is a more recent development, enabled by the introduction of 
electronic exchanges and allowing push-button dialling. It uses pairs of 
tones to represent each dialled number.