Keys are small metal objects used to open locks. They come in various shapes and sizes, designed to fit specific locks. When a key is inserted into a lock and turned, it aligns the internal mechanisms, allowing the lock to open. Keys are commonly used for doors, cars, and safes, providing security and access control. In addition to physical keys, there are also digital keys, such as those used in smartphones and computers. These digital keys, often referred to as passwords or access codes, help protect sensitive information and ensure that only authorized users can access certain data or devices.