What are the three types of vaults that were used?

The three types of vaults commonly used in architecture are the barrel vault, the groin vault, and the ribbed vault. The barrel vault is a continuous series of arches that creates a tunnel-like structure. The groin vault is formed by the intersection of two barrel vaults, producing a more complex space. The ribbed vault features a framework of ribs that support the vault's surface, allowing for greater flexibility in design and the incorporation of decorative elements.