touch and go's are just like a normal landing, but you don't stop the airplane completely and continue taxiing to the gate. Instead you advance the thrust levers and take off.
You touch down on the runway - and go up in the sky again
These operations are done mostly as a practice exercise for trainees.
Talkin about touch-and-go's. I was just doin a practice lap today ( selected the reamin in pattern option ) and forgot to change it to a full stop. When I landed I realised that I would have to hcange to ground freq. manually ( which usually works ) but I couldnt use it.
Then after a while I noticed that ATC was instructing aircraft to hold short because I was apparently still on the runway.