Security zones, which are found in Internet Explorer, allow a user or system administrator to divide websites that a user visits into several groups with a suitable security level. There are four security zones found in Internet Explorer: Internet, Local Intranet, Trusted Sites, and Restricted Sites. Each zone or group has four security levels: High, Medium, Medium-Low, and Low. These levels determine the type of content a user can download and run. Security zones allow users to set the appropriate level of security for the various types of Web contents that they are likely to visit. For any zone, a user can configure the security level, modify the security defaults, or use custom settings for other configurations. All the security zones with their default security levels are described as follows:
- Internet zone: All sites on the Internet that are not in the Trusted or Restricted Sites zones are included in this zone. The default security level for the zone is Medium.
- Local Intranet zone: This zone includes all sites inside an organization's firewall (for computers connected to a local network). The Local Intranet zone is also home to Web applications that need access to the user's hard disk. The default security level for the zone is Medium.
- Trusted Sites zone: This is the zone where a user specifies Internet sites, which are trusted by the user. These sites might include corporate subsidiaries or perhaps the website of a trusted business partner. The default security level for the zone is Low.
- Restricted Sites zone: This is the zone where a user specifies sites that he does not trust and wants to restrict. The default security level for the zone is High.
Note: Except the Internet zone, all the other zones do not include websites by default. Websites must be placed manually into these zones. A user or an administrator can assign a website to a zone with a suitable security level. Whenever one attempts to open or download any content from the Web, Internet Explorer always checks the security zone's settings and behaves according to the applied settings.
