Key duplication is the process of creating a duplicate copy of a key. This can be done using a key duplicating machine, which is a special tool that can cut a new key to match the exact specifications of the original key.

Key duplication is often used when someone wants to have an extra set of keys for their home, car, or office, or when they need to replace a lost or damaged key.

Key duplication can also be useful for making copies of keys that are hard to replace, such as antique or collectible keys.