WYSIWYG stands for What You See Is What You Get.
If you have used a word processor (such as Microsoft Word) before you will have worked with a WYSIWYG editor.
When you edit a Microsoft Word document, the content on your computer closely replicates the final printed product. What you see on your screen is what you expect to get when you pick up your document from your printer.
The same is true online. What you see in the editing interface as you are creating your pages should be what you get once you have published your pages online.
