Breadth-first search (BFS) and depth-first search (DFS) are two fundamental graph traversal algorithms. BFS explores a graph level by level, visiting all nodes at a given depth before moving to the next level. This makes BFS ideal for finding the shortest path in an unweighted graph. DFS, on the other hand, explores as far as possible along one branch before backtracking, which makes it more suited for tasks like detecting cycles or exploring all possible solutions in a search space. DFS can be implemented recursively or iteratively using a stack, while BFS uses a queue. Understanding the difference between these two algorithms helps in solving graph problems efficiently.