(n.) A secret series of characters that enables a user to access a file, computer, or program. On multi-user systems, each user must enter his or her password before the computer will respond to commands. The password helps ensure that unauthorized users do not access the computer. In addition, data files and programs may require a password.
Ideally, the password should be something that nobody could guess. In practice, most people choose a password that is easy to remember, such as their name or their initials. This is one reason it is relatively easy to break into most computer systems.