Categories are groups that help organize and classify items based on shared characteristics or features. For example, in a grocery store, items are categorized into sections like fruits, vegetables, and dairy. This organization makes it easier for shoppers to find what they need. In various fields, such as science and art, categories help in understanding and analyzing information. In biology, living organisms are categorized into groups like mammals and reptiles. Similarly, in literature, books can be categorized by genre, such as fiction or non-fiction, aiding readers in selecting their preferred material.