Special Forces vs special operations forces — what's the difference?

Special operations forces (SOF), or more simply referred to as special operations, refers to all units assigned under the U.S. Special Operations Command (SOCOM), which includes U.S. Naval Special Warfare, Air Force Special Operations Command, Army Special Operations Command, and Marine Special Operations Command.
That means everyone from Air Force Combat Controllers to Navy SEALs to Army Rangers are referred to as special operations. Of course, there are other secretive units under the SOCOM umbrella, and they are considered SOF, too.
Whereas special operations forces is the generic term for all, well, SOF, Special Forces is a proper noun that refers to a very specific unit in SOCOM. Comprised of the 1st, 3rd, 5th, 7th, 10th, 19th, and 20th Special Forces Groups, you can identify Special Forces soldiers by their distinctive green beret. No one else in the U.S. military is called Special Forces.

I never really thought it was that hard to differentiate them, MAJ Dale E. Wilson, Ph.D.!

Well...there are Special Olympics, Special Education, then well, there are Special Forces...that sums it up.

SFC Bernard Walko Lt Col Charlie Brown LTC Trent Klug CMSgt Marcus Falleaf Cpl Vic Burk SMSgt Lawrence McCarter CMSgt (Join to see) Sgt (Join to see) PO1 H Gene Lawrence LTC David Brown SSG Paul Endes LTC Trent Klug SFC John Davis