Backtracking is a technique used to solve problems that involve exploring all possible solutions in a search space. It is particularly useful in problems like generating permutations, solving puzzles, or finding subsets. The key idea is to build a solution incrementally and backtrack (undo) decisions when you realize they won't lead to a valid solution. Each step tries all possibilities for the current position and recursively solves the smaller subproblems. When combined with pruning (eliminating unpromising paths early), backtracking can efficiently explore large search spaces. Mastering backtracking allows you to solve complex combinatorial problems by systematically exploring every possible solution.