Don't Be Talking About My Wiki (or Translation Please)

I read the following on The Starry Dynamo's site. It sounds fascinating - AND I HAVE NO IDEA WHAT SHE IS TALKING ABOUT :-) . Translation anyone? And I hate to ask, but, what is a wiki? I just want to know if I should be concerned about somebody talking about my wiki that way.

"I am one week out with my instance of MediaWiki on a WAMP stack and am surprised at how easy it is to manipulate the CSS and PHP. Particularly with CSS it is very easy to customize the look and feel of your wiki. I consider myself to have above average technical skills but was skeptical that I would be able to wade through the language. PHP looks so foreign, but made more sense the longer I stayed in there. I have been experimenting adding color, customizing the sidebar and adding extensions. There are two sites that are great examples of how MediaWiki can be customized."