Okay kiddo, so you know how some people eat meat, like chicken, beef, and pork? Well, pescetarians are people who don't eat those types of meat, but they do eat fish and seafood. They also usually eat other foods like vegetables, grains, and fruits.
Sometimes people choose to be pescetarians because they want to eat more healthy foods and less meat, but they still want to get some protein from fish. Other people choose it because they don't like the taste of meat, or because they want to help protect the environment by not eating as much meat.
Being a pescetarian can have some benefits for a person's health, like getting some important nutrients from fish, but it's important for them to make sure they are still getting all the nutrients they need from other types of food since they aren't eating meat.
Does that make sense, kiddo?