Working within conferences and meetings (mostly those which are international) a conference interpreter will usually perform the same role as a simultaneous interpreter.
It is vitally important, due to the speed at which they must work, that they can understand the subject matter (even better if this can be in-depth). However, having advances interpreting and language abilities is paramount.
Conferences can be tricky to work on, especially when they are scheduled for multiple days, and simultaneous interpreting is mentally tiring, so it is quite common for a conference interpreters to work in pairs or as a part of a larger team.