Backtracking is a problem-solving algorithmic technique that involves finding a solution incrementally by trying different options and undoing the previous steps if they do not lead to a solution. It is a general algorithm for solving some computational problems, most notably constraint satisfaction problems, that incrementally builds candidates to the solutions and abandons a candidate ("backtracks") as soon as it determines that the candidate cannot possibly be completed to a valid solution. Backtracking is a form of recursion, and it is used to solve problems that have multiple solutions.

The backtracking algorithm uses the depth-first search method. When the algorithm begins to explore the solutions, a bounding function is applied so that the algorithm can determine whether the proposed solution satisfies the constraints. If it does, it will keep looking. If it does not, the branch is removed, and the algorithm returns to the previous level. Backtracking is used to solve problems in which a sequence of objects is chosen from a specified set so that the sequence satisfies some criteria.

In summary, backtracking is a problem-solving algorithmic technique that involves finding a solution incrementally by trying different options and undoing the previous steps if they do not lead to a solution. It is a general algorithm for solving some computational problems, most notably constraint satisfaction problems, that incrementally builds candidates to the solutions and abandons a candidate ("backtracks") as soon as it determines that the candidate cannot possibly be completed to a valid solution. Backtracking is used to solve problems that have multiple solutions, and it uses the depth-first search method.