The name of this field is an abbreviation of the phrase “What You See Is What You Get”. On the frontend, this field looks like a common editing WordPress window with a toolbar at the top. Using this window, the users can add some styled text, HTML coding, or another type of content to the form.
If you have installed the JetStyleManager plugin, the Block Style button will appear in the top right corner of the editing window. Here are the styling settings you can meet there: