The buildings of the Romanesque time period can be characterized by rounded arches whereas the Gothic buildings had pointed arches known as ogives. The Gothic structures are supported by flying buttresses and ribs, which were put in place to replace the thick walls that can be seen in Romanesque buildings. In Romanesque cathedrals and chapels, barrel vaults were quite common and groin vaults were used in Gothic. Another differentiating factor of the Gothic time period are the ornate Rosettes that are common throughout religious architecture. The Gothic buildings were very decorated and had large stain glass windows, which served the purpose of letting light in, but they also had a narrative function.