Other forms: visitors
A visitor is someone who is in a place temporarily. If you spend a week on an island during the summer, you're a visitor there, unlike the people who live on the island year-round.
When you visit someone, you're a visitor in their home, and if someone visits your school, whether to put on a puppet show or a book fair or a presentation about safety, they're a visitor too. It's also common to refer to an opposing sports team as visitors when they come to play on your team's home turf — but when your team travels for an away game, you're the visitors.