Many problems need you to consider every possible selection of items, like all teams you can form from a group. Backtracking with a take-or-skip choice for each element generates all 2ⁿ subsets cleanly. Use it when n is small, roughly up to 20, and you truly need every combination. If you only need the best or the count of subsets meeting a condition, DP such as knapsack is usually far faster.