A subset is a set that contains some or all elements of another set, known as the "superset." For example, if we have a set A, B, C, the subsets could include A, B, C, or even the empty set {}. Every set is considered a subset of itself, and the empty set is a subset of every set. In mathematics, subsets are important for understanding relationships between different sets. The concept is often used in various fields, including statistics, computer science, and logic. Identifying subsets helps in organizing data and solving problems related to grouping and classification.