This section of the backing tracks is dedicated to "Loops". Loops are short pieces of  "music" that can be played over and over again. A lot of music is based on "samples" and "loops" these days.

R&B and Rap / Hip-Hop are good examples of the usage of loops (mostly drum loops).

While you can go the same route and learn to use loops in music production software like Steinberg Cubase, Sonar, Ableton Live and the like, they can also be used to make your guitar exercising more enjoyable...