Question

What is the difference between a tree and a graph?

Answer 1

trees have leafs and graphs don't....

Answer 2

A tree is a type of graph that does not have any cycles and there is only one path between any two vertices.

Answer 3

I would say that the two points above are identical for undirected graphs/trees, but I don't think I've ever heard of a directed tree anyway.

Answer 4

A graph is a set of branches and vertices which may or may not contain loops/cycles within it.

A tree is a graph which consists of all the vertices of the main graph along with branches(edges) which connect all the vertices together( only once). There can be many trees for a given graph.