Is Skype “Full Duplex”?

What an antiquated term: Full Duplex. I don't know if that term is used anymore but what i mean is this:

I use Skype on many many voice calls, either to other Skype users or to telephone. It seems to me that while the other person is talking, I cannot interrupt them. In other words, either I am talking or I am listening, but not both.

Am I mistaken? Or is my Skype set up incorrectly?

Full Duplex is a term that used to mean, maybe still means, that both parties to a connection can be active at the same time. Last time I used it, it was in reference to a teletype machine!