Final answer:
In graph theory, a self edge is also called a loop, which is an edge that connects a vertex to itself, different from a cycle, circuit, or multigraph.
Step-by-step explanation:
A self edge in graph theory is also called a loop. This term refers to an edge that connects a vertex to itself. Different types of edges and vertices are studied in the branch of mathematics known as graph theory, which is used to model relationships between pairs of objects. While a self edge, or loop, is an edge that starts and ends on the same vertex, it's important to distinguish this from a cycle, which is a path of edges and vertices wherein the only repeated vertices are the first and last vertices. A circuit is similar to a cycle but emphasizes the return to the starting vertex, and a multigraph is a type of graph where multiple edges can exist between the same set of vertices.