Firefox 101 - #10 - Online Safety and Security in Firefox
Description: Firefox offers a good balance of security and convenience. When visiting a web site, for example, your banking site, you can view the security certificate and other information associated with that site.
For sites that don't contain quite such personal and personally identifying information, you can opt to have Firefox remember passwords for you. This is convenient but not recommended for things like online banking, sensitive email accounts and so on.