An occupant is someone who lives in, uses, or fills a particular space. The occupants of a house are the people who live there, whether they own it or rent it. The occupants of a car are everyone riding inside it. A classroom's occupants are the students and teacher using that room at the time.

When you occupy a space, you take it up and use it, at least temporarily. The previous occupants of your bedroom might have been your older siblings before they moved out. A hotel room has different occupants each week as new guests check in.

Occupant works for any kind of space or position. A bird is the occupant of its nest. The occupants of the front row at a concert are the lucky people sitting closest to the stage. You'll often see the word in official contexts: a building inspector might count the number of occupants to make sure the space isn't overcrowded, or a news report might mention that all occupants of a vehicle were wearing seat belts.

The word simply identifies who's in a space without suggesting anything about ownership, permission, or how long they've been there.