In Mathematics and Computer Science, the graph theory is just the theory of graphs basically overall. It's basically the relationship between objects. The nodes are just lines that connects the graph. There are a total of six nodes in a family branch tree for a graph theory basically.

Nothing, but it has significance in graph-theory.

A tree in which one vertex called the root, is distinguished from all the others is called a rooted tree.

Gregory Lawrence Chesson has written:

'Synthesis techniques for transformations on tree and graph structures' -- subject(s): Data structures (Computer science), Graph theory, Trees (Graph theory)

defines in graph theory defines in graph theory