What is the difference between Best Case, Average Case, and Worst Case complexity?

Best-case complexity represents the minimum work an algorithm performs for favorable input. Average-case complexity represents expected performance across a defined input distribution. Worst-case complexity represents the maximum work required for any valid input of a given size.

In engineering decisions, worst-case guarantees are especially important for systems with strict latency or reliability requirements. Average-case analysis is useful when the workload distribution is known and realistic.