Industry folk use both terms. Sometimes they interchange them freely or equivocate withoutrealizing it. Sometimes they draw sharp divisions between these two functions of a business.
The two are linked but different disciplines -- and require different mindsets and playbooks to win.
I had the real pleasure of talking about this topic with George Szundi, of Natero, a customer success platform for B2B companies. You can read the full write-up here on Natero's blog, or read the cliff's notes below for how success and support differ on in a few key areas.