CKEditor is an online WYSIWYG editor that produces clean, standards-compliant HTML code. This means that you can write some text in the editing area and format it in a few simple clicks of the toolbar buttons without knowing the ins and outs of the HTML syntax.
This is how a sample text appears in the editing area:
Since the source code view is not read-only, you can also edit your document while in this mode.
Do remember though that HTML editing is an advanced feature and its use should be limited to users with knowledge of the HTML markup language. CKEditor lets you format your document or insert media like images or links without worrying about the source code and tags.