Crossing Numbers of Graphs

The crossing number of a graph is a classic concept in graph theory that refers to the minimum number of edge crossings in a drawing of the graph in the plane. When a graph is drawn on a two-dimensional surface (like a piece of paper), edges can sometimes cross over each other. The goal is to find a layout of the graph that minimizes these crossings. Here's a more detailed explanation: 1. **Graph**: A graph consists of vertices (or nodes) connected by edges (or links).