A cafeteria is a big room where you can go to eat different kinds of food. Imagine it like a big restaurant in your school or at work where everyone goes to eat their meals during the day.
Instead of ordering food from a menu like you do at a restaurant, you get to walk around and pick out the food you want on your own. Some cafeterias have big tables where you can sit and eat with your friends while others may have smaller tables or chairs to sit at.
There are usually different stations in the cafeteria where you can find different kinds of food like pizza, sandwiches, salads, and fruit. There might even be a special section just for desserts!
When you get your food, you take it to a cashier or a machine that scans your food to pay for it. Sometimes you might have a special card or account that you use to pay for your food instead of cash.
Overall, a cafeteria is a place to go eat food with lots of options to choose from and different ways to pay for it.