You can set Firefox to remember your passwords for sites you visit, however, you shouldn't enable this if you are on a public computer.
1) Open the menu.
2) Go to Options.
3) Click Options.
4) Click the Security tab.
5) Check the box next to Remember passwords for sites.
6) Click Exceptions.
Firefox will not save passwords for any sites listed here. We'll see how to add exceptions later in this video.
If you choose to use a master password, all sensitive information will be stored under a single password which you will be asked to enter once per session.
If you have no password set, you will need to create a new one by typing it here.
7) Click OK.
8) Click Saved Passwords.
Any passwords that have been saved will show up in the list.
9) Click OK.
10) When a password is saved, this icon will be displayed next to the address bar. Click it to view options.
11) Click to expand the menu.
Since passwords are remembered automatically, the only other option we have is to never remember passwords for this site. Selecting this option will add this site to the exceptions list we saw earlier.