They are different versions of the same software. Originally it was Acrobat Reader then they changed it Adobe Reader mid 2000’s and then to Adobe Acrobat Reader in mid 2010’s.

Thanks, @Lightlyseared . Now what is Adobe Acrobat DC?

Adobe Acrobat DC is the Pro version of Acrobat that is part of the Adobe Creative Cloud monthly subscription plan.

It has many more features than the free Reader version.

Adobe acrobat DC (Document Cloud) is how you buy acrobat now as a subscription. You can get it standalone or part of Creative Cloud.

It slows you to create PDFs instead of just read them however a lot of programs (word for example) now let you save files as pdf so unless you need the additional features it’s probably not worth paying for.

The reason I asked is that I have Adobe Acrobat DC, but I’ve never paid for any subscription. So I’m not sure I understand what @cookieman and @Lightlyseared are saying.
However, I do note that there some features that are not enabled, but I CAN sign documents and I CAN edit.