What are these "custom fields" I see imported with Divi Den Pro Layouts

Hypothetical situation where you might encounter this...

Inside WordPress admin, on the page edit screen you import a layout. 
After uploading a layout or module in the Divi editor, you see custom fields imported too.
See screenshot below.

For example on the "Best friends" blurb, the following fields/classes are loaded:

• ddp-css-freddie, 
• freddie-best-friend-blurbs

What are these and do I need them? Can I remove them?

• No you should not remove them because that is how the Divi Den Pro plugin knows what css to load for the widget/modules you use on a page.
• This is the leanest possible way for us to make custom layouts and allow you to import and use what you want on any page. And allow us to publish updates and style fixes to those layouts/modules when required. All you have to do is update the plugin to get those fixes.
• Divi Theme updates often (which breaks stuff) then we need to make fixes to old layouts - so you don't have to. 
• And we might even make improvements to say, a mobile view for IOS - those classes/fields allow us push updates to you on 50 different sites where you might have used that module. This method is scalable. Doing it manually is not.

More details here: How the code loading works