What points are served from the deuce court in tennis?

The sides of the court are named according to the score. When the score is forty-forty, it's referred to as "deuce." When playing a deuce point, the server serves from the right side of the court. Thus, the right side of the court is considered the deuce side.

When the score is ad-in or ad-out, the point is played from the left side of the court so that side is the ad side.