Apache Authentication Module Functionality
Apache provides the basic framework and directives to perform authentication and access control. The authentication modules provide support for validating passwords against a specific back end. Users can optionally be organized in groups, easing management of access control rules.
Apache provides three built-in directives related to authentication that will be used with any of the authentication modules: AuthName, AuthType, and Require.
AuthName accepts a string argument, the name for the authentication realm. A realm is a logical area of the Web server that you are asking the password for. It will be displayed in the browser pop-up window.
AuthType specifies the type of browser authentication: basic ...