Bicycle pedals have two jobs. First, they harness the power of your legs into a force used to propel the bike. This is probably the most important. Secondly, they are meant to keep your foot in the proper place.
Now, for those individuals who do not spend a lot of time on their bicycles, the bicycle pedals on a normal bike will do just fine. However, the longer your feet are connected to bicycle pedals the more important it is to have the right set of bicycle pedals.
Bicycles now come with different types of bicycle pedals. Some pedals have are plain. They are just a pedal with no device to keep them in place. These are fine for normal rides around the park or down the street.
Some bicycle pedals have straps and some might also include toe clips. Toe clips are like steel or more often plastic, cases at the top of your bicycle pedals that allow you to slip your feet into them. These toe clips may be tightened with a strap and are used to keep your feet in the right place. This is for serious bicyclers who may be taking longer bike rides that can leave them very tired. In these situations, it is easier for your feet to slip and become entangled in the bicycle wheels.
If you would like to try a system that many bicyclers find more efficient, you may want to try clipless bicycle pedals. However, you do have to buy special shoes to clip onto these pedals. Is is worth buying special shoes? That is up to you but the system does make for an easier start and finish allowing your shoe to snap onto the bicycle pedals and snap off by shifting your foot in a certain way to release it.