Face-to-face (plugin)

I'm not sure what you mean by synchronous, but the best way to describe the face-to-face module is as a booking and attendance system for meetings or training sessions that occur outside moodle (i.e. real-life training rather than online).

The main help page is here:

http://docs.moodle.org/en/Face-to-face_module

Which includes this page that gives a walk-through of the features available:

http://docs.moodle.org/en/Face-to-face_walk_through

No, it is for using Moodle to schedule face-to-face sessions in the real world.

The only Synchronous bit build into Moodle is the Chat module.

Moodle will integrate with synchronous communication tools like Elluminate, DimDim, and so on.

That makes sense because Moodle is basically a web site, and synchronous things work better with a rich client and a special sort of server.