Mountain Bike Brakes are essential to the sport of mountain biking. There are two kinds of brakes; Disc and Rim. Disc brakes are more efficient, but heavier, while rim brakes are easier to manage.
If you want the lightest set-up you can have, and are willing to accept small variances in brake performance, or if a low price is really important, choose rim brakes over disc brakes. Mountain bike rim brakes have gone through several design changes over the years. They started with the original cantilever brakes, went through the dark U-Brake years, and are now known as V-Brakes. V-Brakes work well in most conditions.
Rim brakes have some drawbacks. They require straight un-damaged rims to perform their best. Rim brakes perform poorly in wet or muddy conditions, and that’s where disc brakes are more efficient.