What is "spanning tree"

n. (context graph theory English) a tree structure which includes all vertex of a graph

In the mathematical field of graph theory, a spanning tree T of an undirected graph G is a subgraph that is a tree which includes all of the vertices of G. In general, a graph may have several spanning trees, but a graph that is not connected will not contain a spanning tree (but see Spanning forests below). If all of the edges of G are also edges of a spanning tree T of G, then G is a tree and is identical to T (that is, a tree has a unique spanning tree and it is itself).

Spanning tree can refer to:

• Spanning tree (mathematics), a tree which contains every vertex of a more general graph
• Spanning tree protocol, a protocol for finding spanning trees in bridged networks