Barrel vault - the simplest vault, also called a wagon or tunnel vault. A continuous vault usually semi-circular in section.
Boss - a knob or projection covering the intersection of ribs, usually decorated or carved, very often foliated.
Cell - a compartment contained by ribs, usually infilled in stone, latterly in brick. Also known as a webb.
Cross vault - where two barrel vaults of identical shape intersect at right angles. Also known as a groined vault.
Fan vault - resembles a fan! Constructed in concave ribs of equal length, which spring from a central point. The ribs meet, or nearly meet at the apex or crown of the vault.
Groin - sharp edges where surfaces meet in a groin vault, not covered by ribs.
Stelar vaulting - a name given to vaults where the ribs converge in star - like patterns.
Rib - the projecting band on a vault ceiling, usually structural, can be decorative.
Transverse arch - the arch which separates one bay of a vault from another, often decorated.