Usually a foyer is a large, specially designed hall, but sometimes it is a corridor surrounding the main hall. It is furnished and big enough to enable spectators to stroll, get together and rest. Foyers are commonly adorned with art works, permanent or temporary exhibitions related to the activity of the institution, and a refreshment room or buffet. Moreover, the foyer can be the main place of some events such as vernissage, meetings with the artists, actors' benefit, etc.
A foyer in a house is usually a small entry area or room by the front door. Other public rooms such as the living room, dining room, and family room typically attach to it, along with any main stairway. It was initially intended as an "airlock", separating the fireplace-heated rooms from the (colder, in winter) front entrance, where cold air infiltration made for cold drafts and low temperatures. It is commonly used for outer garment and umbrella storage for both residents and guests.
The word foyer comes from the French language, meaning "the place where the fire is kept".