Vestibule (architecture)

A vestibule is like a little room that you usually walk through before you get into a bigger room. It's like a space in between two rooms.

For example, think about when you go into a large church. There's usually a small area with doors that you go through before you enter the bigger room where people sit to worship. That little area with the doors is the vestibule.

Or, think about entering a house. There's usually a small area where you take off your shoes or coat that's in between the outside and the bigger room of the house. That's also a vestibule.

The vestibule is usually a small, enclosed space that helps to separate the outside world from the inside world. It's like a transition zone, kind of like a waiting area before you go into the main area.