In terms of desktop publishing, page layout programs are WYSIWYG. When you are composing a page you are usually seeing more or less the same fonts, colors, and the same overall layout that you will have when you print the page. Iit should sometimes be called "what you see is almost what you get or fairly close or somewhat similar". What you see on-screen can never exactly duplicate what the printed page will look like.
Before the advent of desktop publishing word processing software only displayed plain text. The computer user added visible coding to tell the printer we wanted a larger font for a headline or that a certain block of text should be centered as well as what the margins should be but until it printed we weren't entirely sure what the page was going to look like. With WYSIWYG you have a fairly close approximation on-screen of what will print.
