A random password generator is software program that takes input from a random or pseudo-random number generator and automatically generates a password.
Password strength is a measure of the effectiveness of a password against guessing or brute-force attacks.
In its usual form, it estimates how many trials an attacker who does not have direct access to the password would need, on average, to guess it correctly.
The strength of a password is a function of length, complexity, and unpredictability.
Using strong passwords lowers overall risk of a security breach, but strong passwords do not replace the need for other effective security controls.