Beginners in the Learn to Fence course start fencing with foil.

Foil is a thrusting weapon - hits can be scored with the point, but not the edge of the blade. The valid target is the torso of the body. A hit arriving on the mask, arms or legs is ‘off-target’ and if it has priority, will prevent a later hit on target by the opponent from scoring. 

Foil is known as a 'priority' weapon. The first person to start the attack has priority until they miss, or are parried, or stop attacking. With the other fencer using parries, footwork and tactics, first to attack does not mean first to score a point.

The blade is 90cm long and has a small guard to protect the fingers. Hits are scored by depressing the button on the tip of the blade, and electronic scoring equipment distinguishes on target from off target. Priority is decided by a referee in competition matches.

A foil bout has frequent movement back and forward with the fencers threatening to hit one part of target, changing to threaten another area to distract their opponent and conceal their intent, while also moving to block attacks threatened by their opponent. An attack begins when a fencer believes they can score a hit - they may not always succeed!

Foil is derived from short sword which was a practice weapon 300 years ago. 

For more information, see the Wikipedia entry on Foil.