Okay, kiddo, tapioca is like tiny, little balls that come from the cassava plant. This plant grows in warm countries like Brazil and Africa, and the balls are made by extracting the starch from the cassava root. When the starch is extracted, it's put into hot water and then cooled down to make those little balls we call tapioca.
Tapioca can be used in a lot of different ways. Some people make pudding with it, others use it to thicken soup or stew. It can even be turned into flour and used to make bread or cakes.
Some people think that tapioca is really healthy because it's gluten-free and low in fat. But it's also high in carbs and doesn't have much nutritional value on its own. So while it can be part of a healthy diet, it's important to eat other nutritious foods too.
So there you have it, tapioca is these little balls made from a plant called cassava that can be used in lots of different ways in cooking.