Passwords have been in use for different purposes over a long period of time. We are aware that in earlier times, sentries would not allow anyone inside a location if he failed to say the password. Today, we have to use passwords in different steps of our life. They are now used to control access to protected computer operating systems, mobile phones, ATMs, cable TV decoders, and a great many other applications. One who uses a computer on a regular basis has to use passwords for a number of purposes, like retrieving e-mail from servers, logins to computer accounts, accessing databases, networks, and web sites. You may even require a password if you want to read your newspaper online.

A password, however, does not necessarily have to be actual words. Passwords not formed out of actual words are difficult to guess, meaning they are safer and therefore more effective. One should note that passwords are often used to describe what can appropriately be called pass phrases. The term