Each time you enter a user name and a password on a Web site, Firefox offers to store this data. A pop-up at the top of the page opens, asking you whether you want Firefox to remember the password. If you accept by clicking Remember, the password will be stored on your hard disk in an encrypted format. The next time you access this site, Firefox will automatically fill in the login data.
To review or manage your passwords, open the password manager by clicking Edit › Preferences › Security › Saved Passwords in the menu bar. The password manager opens with a list of sites and their corresponding user names. By default, the passwords are not displayed. You can click Show Passwords to display them. To delete single or all entries from the list, click Remove or Remove All, respectively.
To protect your passwords from unauthorized access, you can set a master password that is required when managing or adding passwords. In the menu bar, click Edit › Preferences, choose the category Security and activate Use a Master Password.