SELinux Policy Editor is Composed of Simplified Policy and GUI(an add-on module for Webmin). This module enables Web-based edit of the security rules of Security-Enhanced Linux(SELinux).
SELinux brings very strong security, but the definition of security rules is very complex and difficult to deal with. Without SELinux Policy Editor, you must edit many configuration files to define the security policy for your system. This is hard task. SELinux Policy Editor prevents mis-defining or lack of security rules, because this module provides more easily understandable expressions of security policy on Web browser.
The key concept of SELinux Policy Editor is Simplified Policy. You can use Simplified Policy from command line. For detail, see "Configuring SELinux by Simplified Policy".