What is a graph?
Consists of a set of vertices or nodes.
These vertices can be connected by edges or arcs.
What is the degree/order of a vertex?
The number of edges coming out of it. If the degree of a vertex is even we call it an even vertex. If the degree of a vertex is odd we call it an odd vertex.
What are Isomorphic graphs?
Two graphs are isomorphic if there is a one-to-one correspondence between their vertices which preserves adjacency. (The same graph, possibly laid out and/or labelled differently.)
What is a subgraph?
A graph whose edges and vertices are contained within the main graph.
What is a walk?
A sequence of connecting edges in a given graph.
What is a trail?
A walk in which no edge is listed more than once.
What is a path?
A walk in which no vertex is visited more than once
What is a cycle?
A path that finishes where it started
What is a connected graph?
A graph where there is a path to all of its vertices
What is a simple graph?
A graph where there are no loops or repeated edges
What is a tree?
A connected graph with no cycles