Okay, so imagine you're going camping with your family. You set up your tent, but sometimes it can get a little dark inside. That's where a chum comes in!
A chum is a special type of tent that you put over your regular tent to make it like a "double-layered" tent. It's made of a special see-through material that lets in lots of light, so you can see inside your tent better.
Some chums also have mosquito netting around the sides to keep bugs out, and some even have a special door that you can use to get in and out of your tent without having to go outside.
It's like having a super cool tent jacket that makes your regular tent even better!