Many bikes, especially mountain bikes, use V-brakes (also called direct-pull or linear-pull brakes). In this powerful brake design, the cable enters the brake area from the side, rather than from the top as is common in other brake styles.
This brake cable attaches to each of the arms of the brake mount, which pivot on the frame of the bicycle. When the cable is pulled, the arms of the brake mount are pulled together and the brake pads are brought into contact with the rim of the tire. This design provides a good deal of stopping power and is common on mountain bikes for its usefulness during rapid trail rides.
V-brakes don't take much to get out of alignment or have other issues. Luckily, adjusting this design is easy and straightforward.