NetworkX is a Python library designed for the creation, manipulation, and study of complex networks. It provides tools to work with both undirected and directed graphs, allowing users to analyze the structure and dynamics of networks easily. With NetworkX, users can visualize graphs, compute various metrics like centrality and clustering coefficients, and perform network algorithms. It is widely used in fields such as social network analysis, biology, and computer science, making it a versatile tool for researchers and developers interested in network theory.