Set intersection is a mathematical operation that identifies the common elements between two or more sets. For example, if we have two sets, A, B, C and B, C, D, the intersection of these sets is B, C because these elements appear in both sets. In set notation, the intersection is often represented by the symbol ∩. The result of the intersection is itself a set that contains only the elements that are shared. This concept is widely used in various fields, including mathematics, computer science, and statistics, to analyze relationships between different groups of data.