How can I tell if a machine's single analog audio socket is out-only or a "combo"?

The ASUS VivoMini VC66R has only one socket for an audio jack: How can I tell whether this will support only audio-out (headphones), or combination audio in-and-out (in which case I can use an adapter/socket splitter )

Question by einpoklum on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.