The document describes Prim's algorithm for finding a minimum spanning tree (MST) in a weighted, undirected graph. Prim's algorithm is a greedy algorithm that grows the MST by iteratively adding the closest vertex to the tree. It starts with a single vertex and adds the neighboring vertex with the lowest weight edge until all vertices are included in the tree. Pseudocode is provided to illustrate the steps of Prim's algorithm, which initializes all vertex keys to infinity except the starting vertex, then extracts the minimum key vertex and updates neighboring vertex keys if a lower weight edge is found. Examples are shown applying Prim's algorithm to find the MST of a sample graph.