Cyclomatic complexity is a software metric used to measure the complexity of a program's control flow. It quantifies the number of linearly independent paths through a program's source code, helping developers understand how complicated a piece of code is. A higher cyclomatic complexity indicates more potential paths and, therefore, a greater likelihood of errors and maintenance challenges. This metric is calculated using the formula: M = E - N + 2P, where M is the cyclomatic complexity, E is the number of edges, N is the number of nodes, and P is the number of connected components. By analyzing cyclomatic complexity, developers can identify areas of code that may need refactoring or additional testing.