Foresail

A jib is a foresail on a boat, meaning that it is located forward of the mast. The luff of the sail is attached to the forestay, and the clew is usually attached to two sheets which are lead to either side of the boat.

Jib sails can come in different sizes. A jib sail that is large enough to overlap the mainsail is actually called a genoa, not a jib, but the term "jib" is often used for any foresail.