Clique (graph theory)

In graph theory, a **clique** is a subset of vertices in an undirected graph such that every two distinct vertices in the clique are adjacent. In simpler terms, a clique is a complete subgraph where every vertex is connected to every other vertex. More formally, a clique of size \( k \) is a set of \( k \) vertices such that there are edges between every pair of vertices in that set.