Brakes are, fairly self-evidently, one of the most important systems on a bicycle for the safety of the rider and of everyone sharing the roads or trails with them (yes I remember the no-brake fixie era with a certain nostalgia, but leave it in 2009 or on the track please).

There are a bunch of braking systems, but you can rarely mix and match, so just choose the nicest brakes you can afford that will fit with what your frame was designed for, and change the parts as soon as they start getting too worn. Cables are in the Cables and Housing section of this site.

Match lever types to brake types: MTB brakes from the 90s and later aren't inter-compatible with road brakes.