Clarification on the definition of multigraph

Question

If I have a graph that has an edge that straight connects vertice $A$ to $B$ and another that connects vertice $A$ to $C$ then to $B$ is it considered a multigraph?

Clarification will be much appreciated. Thanks.

Answer 1

If I understood correctly, the edges make a triangle. That is not (necessarily) a multigraph. In a regular graph there may be many paths between two vertices. It is only single edges that cannot be doubled. If you want to disallow any such multiple paths, however, your graph is called a tree (as long as it's connected).

Answer 2

from wikipedia:

"In mathematics, and more specifically in graph theory, a multigraph (in contrast to a simple graph) is a graph which is permitted to have multiple edges (also called parallel edges[1]), that is, edges that have the same end nodes. Thus two vertices may be connected by more than one edge." so for example ([a,b,c](a,b),(b,a),(b,c),(c,b)) has both b connected to c, and c connected ( via a different edge) to b. that would make it a multigraph.

Answer 3

From Wikipedia:

A multigraph (in contrast to a simple graph) is a graph which is permitted to have multiple edges (also called parallel edges), that is, edges that have the same end nodes. Thus two vertices may be connected by more than one edge.

I think maybe you are mistaking hypergraph for multigraph:

A multigraph is different from a hypergraph, which is a graph in which an edge can connect any number of nodes, not just two.