Medic
The medic is a maniacal German scientist who is capable of healing his teammates and making them invulnerable for short periods of time. In 6v6, the medic makes up a key component of the combo, along with the pocket soldier. In highlander, the combo usually consists of a medic, heavy, and demoman. As the medic does not need to focus on aim, medics generally act as callers for their teams. Medic duties generally include keeping the team fully buffed, timing and leading pushes, and tracking enemy ubers.
6v6
Main Article: Medic (6v6) The Medic is the key target in 6v6. His ability to heal his teammates and turn the tide of battle with his Ubercharges.
Highlander
Main Article: Medic (Highlander) The Medic has the same role as he does in 6v6; healing his teammates and using his Ubercharges to turn the tide of a match.