Before revision: 280 px|An airlock on board the Space Shuttle An airlock is a room or compartment which permits passage between environments of differing atmospheric pressure or composition, while minimizing the mixing of environments or change in pressure in the adjoining spaces .
After revision: 280 px|An airlock on board the Space Shuttle An airlock is a room or compartment which permits passage between environments of differing atmospheric pressure or composition, while minimizing the changing of pressure or composition between the differing environments .