A combination lock is a type of locking mechanism that requires a specific sequence of numbers or symbols to open. Unlike traditional locks that use keys, combination locks rely on a rotating dial or a series of buttons. When the correct combination is entered, the internal mechanism releases, allowing the lock to open. These locks are commonly used for securing lockers, safes, and gates. They come in various designs, including padlocks and built-in locks for doors. Combination locks are popular because they eliminate the need for physical keys, making them convenient and reducing the risk of losing a key.