What is the use : Types of directives that are allowed in .htaccess files
This directive decalres which directives in distributed .htaccess files can override directives from the parent levels (httpd.conf). There are three values can be provided for this directive, those are All, None and FileInfo.
All and FileInfo enables .htaccess file and all ISAPI_Rewrite directives in it.
When this directive is set to None and AllowOverrideList is set to None .htaccess files are completely ignored. In this case, the server will not even attempt to read .htaccess files in the filesystem.This means if you specify AllowOverride none for some directory or virtual host .htaccess files will also be disabled for all subdirectories.
When this directive is set to All, then any directive which has the .htaccess Context is allowed in .htaccess files.