Okay kiddo, imagine you are in a class of other kids. Your teacher wants to know what you all like to eat for lunch. Some kids like sandwiches, some like pizza, and some like mac and cheese. These different groups of kids who like different foods are called "market segments."
The same thing happens in the world of grown-ups who sell things. A market segment is a group of people who have something in common, like their age, interests, or the things they like to buy.
Companies use market segmentation to figure out who their customers are and what kinds of products they might want to buy. For example, a toy company might make different toys for different age groups, like babies, toddlers, and big kids. That way, they can sell the right toys to the right people and make more money!
Does that make sense, kiddo?