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. Users must align the internal gears or pins in the correct order to unlock the device. These locks are commonly used for securing lockers, safes, and doors. They offer a level of security that can be more convenient than keys, as there is no risk of losing a key. However, users must remember the combination to access the locked item.