What is graph theory

Incidentally, the study of such visual models that show the connections and relationships between different objects is known as graph theory.In a basic graph, the circles representing the objects are known as nodes,while the connecting lines are called edges.Researchers studying such graphs ask questions like,How far is this node from that one?How many edges does the most popular node have?Is there a route between these two nodes,and if so, how long is it?