There are many different programs you can choose to use with your controller. For this site, we'll be look at Traktor.

The program is set up so you have a deck A and deck B (just like you were to have two turn tables) and sets up a mixing console in the middle of them. You could essentially just DJ with the program just by using a mouse to maneuver the cross fader, volume knobs and other effects; However, you will have much more control with an actual controller running with the program.