"What you see is what you get."
WYSIWYG acts as a textbox. You can place text, images, tables, links, or macros within a WYSIWYG. You may also format the content within the widget properties.
Once you have a Foundations (like in a Grid Layout) Widget, you can place a WYSIWYG inside. Use WYSIWYG to make titles for your site, write content, add images, or add tables.