Firefox is among the world's safest and most secure browsers. Firefox security and Firefox privacy are covered in this free lesson.
For added privacy, Firefox also offers private browsing, which allows you to browse the web without recording your history or storing cookies. This is a great way to keep your browsing history secret when planning a party or buying a gift for someone who shares your computer.
Private browsing does not make Firefox more secure—it only stops Firefox from saving history and cookies for that session. Don't use a private window to view any websites you wouldn't feel safe viewing in a regular Firefox window.