security zone

Definition of security zone in The Network Encyclopedia.

What is Security Zone?

A feature of Microsoft Internet Explorer that allows users to designate which intranets and portions of the Internet are trusted or distrusted. The more trusted a zone is, the broader the permissions it grants for executing scripts, Microsoft ActiveX controls, and Java applets, and for executing other potentially hazardous actions. Security settings for a zone can be high, medium, low, or custom.

Here are the zones you can configure and their default security settings:

  • Internet zone (medium):
    For sites on the Internet that are considered unsafe and for which access is restricted


  • Local intranet zone (medium):
    For internal sites that are connected to the local network


  • Trusted sites zone (low):
    For Internet sites that are considered safe for unrestricted access


  • Restricted sites zone (high):
    For sites on the Internet that have not been determined either safe or unsafe and are thus considered extremely dangerous


A fifth zone, which is defined as trusted but which cannot be configured, is the My Computer zone, which consists of the local system’s resources.

Graphic S-4. The Security tab in the Internet Options dialog box.