What is the difference between the Digital Subscriber Line broadband and Dial up?

Digital Subscriber Line broadband is a whole world of difference from Dial-up!
Ok so dial up is transmitting tones & data over a phone line, its slow and typical speeds are less than 1mb... so you cant really watch YouTube!
DSL broadband is an "always on" dedicated internet line, and allows much faster connections!
Typically business's might have something like DSL at a minimum, and increasingly home users will have DSL services or similar.

Dialup is pretty archaic these days, and few use them, increasingly being phased out by suppliers and providers as legacy technology.