Answer Description

Wikipedia

A vestibule (also anteroom, antechamber, or foyer) is a small room leading into a larger space such as a lobby, entrance hall or passage, for the purpose of waiting, withholding the larger space view, reducing heat loss, providing storage space for outdoor clothing, etc. The term applies to structures in both modern and classical architecture since ancient times. In modern architecture, a vestibule is typically a small room next to the outer door and connecting it with the interior of the building. In ancient Roman architecture, a vestibule (Latin: vestibulum) was a partially enclosed area between the interior of the house and the street.