Basically it creates a Master Password, behind which all the other passwords and user names are stored. If you would like to see if this is something for you, and you are already using Firefox as your default browser, here is what you have to do:
- click on Tools in the menu bar
- choose Options
- click on "use a Master Password"
It will then prompt you to create a Master Password. Make sure you use a combination of letters and numbers which is at least 8 digits long, and at least one capitalized letter. Once you've done this, Firefox will store all of your passwords with nearly unbreakable AES encryption. Each time you start Firefox and go to a site that requires a saved password, you'll be first prompted for your master password.
For now it works for me, I hope it works for you too !