The Key and Lock

A lock is a device that keeps something closed. A key is the small tool that opens it. Together, they help protect homes, cars, and even treasure chests. Only the person with the right key can unlock the lock.

The First Locks

Locks are very old. The first ones were made about 6,000 years ago in ancient Egypt. They were big and made of wood. The key was also wooden and shaped like a toothbrush. In Roman times, people made metal locks and small keys. Some Romans even wore their keys as rings on their fingers.

How Modern Locks Work

Today, many locks use a system of tiny pins inside. When the right key goes in, the bumps on the key push the pins to the correct height. Then the lock can turn and open. If the key is wrong, the pins block it. Newer locks can also use codes, fingerprints, or phones instead of keys.

Fun Facts

• A famous lock maker named Linus Yale invented the pin tumbler lock still used today.
• Some castles had locks so tricky that thieves could never open them.
• A locksmith is a person who makes and fixes locks.

Did You Know?

The oldest known lock was found in the ruins of an ancient palace in what is now Iraq.