P.S. Here is some more info from http://www.roboform.com/password-manager to understand it better…
What is a password manager?
A password manager is software that helps you organize your logins and passwords, making your internet experience both easier and more secure. With a password manager, you’ll never need to remember or type your logins again.
Why do I need a password manager?
You should be using different secure passwords for all the websites you log into, or at least every website in which you store personal information. The challenge in doing this is that most people cannot remember more than three or four unique strong passwords.
The biggest risk in using the same password across multiple sites is that if one of them gets hacked, your other logins will be compromised as well. In the last year alone, there have been several high-profile data breaches which have resulted in millions of user accounts being exposed.
Using an established password manager like RoboForm allows you to generate unique and secure passwords for each of your logins, then save them so you don’t need to remember or type them again. Not only will you be keeping yourself safer online, but you’ll be taking the hassle out of logging into multiple sites. All you need to remember is your one Master Password!
How does RoboForm protect my master password?
Your Master Password is the one password you’ll need to create and remember as it encrypts and secures all your RoboForm information.
So how do we protect it? We never know it in the first place! Your Master Password is never stored on our servers and only you know it, so there is no way for it to be hacked or stolen by anyone else. Be sure that you don’t forget it!