The three weapons in fencing are the foil, épée, and the saber. Specfic rules, such as where and when a hit (touch) is considered valid, vary from weapon to weapon, but the premise is the same: score touches on your opponent without getting hit yourself, generally by blocking (parrying) the blade.
A fencing bout goes to a predetermined number of touches (usually 5 to 15). The action takes place on a strip and is overseen by a referee. Touches are registered electronically, using weapons that complete a circuit to a scoring device.
With stringent equipment requirements, thorough training, and an emphasis on serious athletics, fencing is an extremely safe sport. The multi-faceted nature of bouting makes it ideal for all ages and body types.
1763 fencing print from Domenico Angelo's instruction book. Angelo was instrumental in turning fencing into an athletic sport.