A set is a well-defined collection of distinct objects, with fundamental operations: union (A∪B), intersection (A∩B), difference (A−B), and complement (A').

Venn diagrams visually represent these operations using overlapping circles, making abstract set relationships immediately visible.

• ›Understanding set operations is foundational for probability theory since probability calculations frequently involve union/intersection of events
• ›The cardinality formula n(A∪B) = n(A) + n(B) − n(A∩B) is a frequently tested practical calculation derived directly from these basic operations