When you enter a gym’s locker room, there are hundreds of lockers. Each has its own combination lock. Without giving it too much thought, you open your locker using the combination only you know, which is the same combination you provided when you signed up at the gym.

Similarly, a password is a shared secret between a user and a service. When the user wants to connect to the service, they identify themselves with their username and prove that identity with the password.

Read full How hackers target your passwords article by Noa Bar-Yosef, Senior Security Strategist at Imperva.