Because there is wide variation in how trustworthy Web sites are, Internet Explorer enables you to assign any files you can open or downloadfrom files on your computer to files on the Internetto "security zones." You can set different levels of security depending on where Web information comes from and how much you trust it.

Many Internet sites are equipped to prevent unauthorized people from seeing the data sent to or from those sites. These are called "secure" sites. Because Internet Explorer supports the security protocols used by secure sites, you can send information to a secure site with safety and confidence. (A protocol is a set of rules and standards that enable computers to exchange information.) When you are viewing a page from a secure site, Internet Explorer displays a lock icon on the status bar.

Internet Explorer can also notify you when you are about to do something that might pose a security risk. For example, if you are about to send your credit-card number to an unsecure site, Internet Explorer can warn you that the site is not secure. If the site claims to be secure but its security credentials are suspect, Internet Explorer can warn you that the site might have been tampered with or might be misrepresenting itself.