Summary

A hash_table maps keys to values using a hash_function that sends a key to an index in buckets. Core ops are insert, search, and delete. Average time is O(1); worst case is O(n) with many collisions. Common collision_resolution methods are chaining and open_addressing. The load_factor tracks how full the table is. When it is high, resize and rehash to keep performance. Good hash_function choice reduces collisions and keeps lookups fast.