Are Sockets Full Duplex?

So for example,

When you send a file from host A to Host B, host B will have to ACK those bytes according to the window size.

But could host B at the same time send host A, a file using the exact same socket ID?

TIA

I would imagine it depends on the application layer. If you think about the OSI, the socket is basically the mapping between port and IP which defines the socket. The application is generally controlling the sending of the file (if we are talking ftp for example).

This would be my guess on the question.