Graph
A graph is a mathematical structure consisting of vertices (nodes) connected by edges (links), used to model pairwise relationships between objects. It is a fundamental data structure in computer science for representing networks, such as social connections, web pages, or transportation systems. Graphs enable efficient algorithms for tasks like pathfinding, network analysis, and dependency resolution.
Developers should learn graphs when working on problems involving relationships, connectivity, or networks, such as social media features, recommendation systems, or routing applications. They are essential for implementing algorithms like Dijkstra's shortest path, breadth-first search, or topological sorting in scenarios like GPS navigation, task scheduling, or data dependency management.