WYSIWYG is pronounced wiz-ee-wig. It’s an acronym for What You See Is What You Get. WYSIWYG is a way of showing you as you type how things will look once they’re published online without bothering you with all the HTML that’s involved.
If you are using Blogger or Typepad, you are using WYSIWYG every time you compose a post using the “Compose Post” tab instead of the “Edit HTML” tab.