When you browse the web, Safari stores information about the websites you visit. If you’ve turned on password saving in AutoFill preferences, Safari also stores any user names and passwords you enter. If you browse the web on a Mac that’s also used by other people, they can view your browsing behavior by reading the history list or the list of stored passwords. To prevent others from gaining access to this information, use Private Browsing.
Many websites also store information on your computer, in cookies and other places. Cookies can be helpful: for example, a gaming website might store information that tells the website who you are, so when you revisit the website, it remembers your scores. However, some websites store tracking cookies and other data so advertisers can show you ads for products that match your interests. To inhibit third parties from viewing this kind of information, use Private Browsing.
When Private Browsing is on, webpages are not added to the history list, the names of downloads are removed from the Downloads window, AutoFill information isn’t saved, and searches are not added to the search field’s pop-up menu. Websites can’t modify information stored on your computer, so services normally available at such sites may work differently until you turn off Private Browsing. Any changes made to cookies are discarded when you turn off Private Browsing.
Plug-ins that support Private Browsing also stop storing cookies and other tracking information.