A Password Generator is a software application or physical device that automatically generates a unique password for a user based on a given input. Commonly, this includes numbers, letters, special characters or words. A random password can also be created manually, with simple sources of randomly-generated randomness like coins or dice, or they could be created using a highly sophisticated computer program. In general, when you generate a password on your own, you have to be very clever in order to ensure that nobody else would be able to crack the code. If a person who knows the password already has the codes, he/she could break into the user's system and gain unauthorized access to the computer's files.