WYSIWYG

WYSIWYG (What You See Is What You Get. Pronounced "Wissy-Wig".) means that what is displayed in your editor is (nearly) the same as what "you get" when you render it. The contrast is if your editor displays control signs like the tags in html:

 this is <b>fat</b>

Above, you find a text containing control signs. Below, you see the same text in WYSIWYG, so, as it would be displayed in a browser:

this is fat

Major classes of WYSIWYG applications are word processors and HTML editors.