Airplanes have various, often redundant braking systems that the pilot should know.
Whenever people think about brakes the first idea that comes often to mind is that of the brakes of a car as a matter of familiarity. In the case of airplanes, the hydraulic braking system could be analogised to the braking system of a car because it is based in the same principles but it is nevertheless, just one of the various that you will find on a plane and it is also a little bit more complex and functional.
For example, the hydraulic brakes of a plane are differential; they are managed by means of pedals, and you have one for the right or starboard side and one left. These differential brakes can then be applied together, to brake the plane in a traditional sense or to brake with one side of the main gear or the other. This helps when turning in very tight circles.
Airplanes like a PA-11 or PA-18 can literally turn on a dime using this technique, which is widely used while taxiing; however, abusing the brakes it is not recommended and using them too much is not seen as a good habit since these brakes tend to overheat and whatever suffers from a lot of effort tends to fail sooner.
Bigger airplanes have attached other systems in addition to the hydraulic brakes. For example, there is something called "auto brakes", which is a system presented by means an instrument in the cockpit. This allows the pilot to preset a certain braking power or strength that will be automatically applied as the plane touches ground.
This is used to diminish the workload of the pilot during the landing operation, and to increase braking effectiveness: Using the auto braking system a B-747 at full load is able to land in about 900 m, albeit if this technique is used not only the brake swill end up being red hot and the plane unusable for a couple of hours, but there could be more damage as well, particularly to the wheels.
Some airplanes have four pedals for the pilot: Two for the rudder and two for the differential brakes associated to the two main gear wheels.