Explain the Banker's algorithm for deadlock avoidance.

Banker's algorithm determines if resource allocation leaves system in safe state (sequence exists where all processes can complete). Data structures: Available (resources free), Max (maximum needs), Allocation (currently held), Need (Max-Allocation). Safety check: find process whose Need <= Available, simulate completion (Available += Allocation), repeat until all complete (safe) or stuck (unsafe). On request, tentatively allocate, check safety, grant if safe else wait. O(n^2*m) complexity.