A foil is a specific type of fencing sword. Foils are used in sport fencing, and they are also the most common blade used in an introduction to the art of fencing. Many fencers have worked with foils at some point in their careers, even if they have gone on to use different blades and fencing styles. Any fencing supply store will keep a wide array of foils, along with grips, blade protectors, and other fencing equipment like protective jackets and helmets.
The foil is descended from older practice blades, which were used to teach people the basic skills of sword fighting before they graduated on to larger weapons. Some fencers still treat foils as practice blades, learning the rules and basics of fencing on a foil before they graduate to a saber or another blade. However, foil fencing has also developed into its own fencing discipline, and many of the world's top fencers fight foil. In competition, foils are usually electrified, so that when they make contact with an opponent's jacket, a light goes on to indicate the hit. This ensures that all blows are counted, even when fencers don't feel them.
The blade of a foil is four sided and extremely flexible, designed for thrusting blows. Most foils are protected with a small rubber or plastic ball at the tip of the blade with prevents a fencer from seriously injuring an opponent. The whippy nature of the foil blade also helps to prevent injuries, as the blade bends when it comes into contact with an opponent. In foil fencing, blows which would be penetrating are considered hits.
There are a number of different handle styles paired with the foil, and you can often see an array in competition, as fencers pick the handles which are best suited to them. Three common classes of foil handles are the French, Italian, and pistol grip. French grip foils have a blocky, curved handle which the fencer wraps his or her hand around, while Italian grip foils have a straight handle attached to supportive crossbars. Pistol grip or orthopedic foils have a curvy, contoured shape which fits the hand of the fencer. In all cases, the hand is protected by a circular guard.
If you are interested in learning sport fencing, you are probably going to want to start out in a foil class. Depending on your level of interest in the sport, you can purchase or rent blades; many people prefer to rent blades in the beginning while they decide whether or not fencing is for them. In all cases, take care of the blades by oiling and wiping them down periodically, and store them responsibly, out of the reach of children and in an area which has minimal humidity.