while doing this for my wallpaper site, i came acros some terms as apache directives.

can anyone tell me what are they and what are they used for and more specifically what are they used for. i visited http://httpd.apache.org/docs/1.3/mod/directives.html and all it says "Each Apache directive available in the standard Apache distribution is listed here. They are described using a consistent format, and there is a dictionary of the terms used in their descriptions available" but that really doenst make much sense to me and im not sure how to use directives in my configurations