What do chair umpires, line umpires and roving umpires do?

From the Officials section of the 2026 Rules of the Court and Tennis Canada's officiating page:

• Chair umpire: responsible for all aspects of their assigned match; applies the Rules of Tennis, Code of Conduct and Tournament Regulations on court; final authority on questions of fact, including overruling a line umpire in the case of a clear mistake.
• Line umpire: assists the chair in deciding whether balls fall in or out, calls foot faults, and performs other duties the chair assigns (for example escorting players to the toilet and preparing and performing ball changes).
• Roving umpire: has jurisdiction over more than one court. Duties include making sure assigned courts are ready for play, enforcing the warm-up time, rules, regulations and Code of Conduct, resolving scoring disputes, overruling line calls and calling foot faults when directly observing the court, and controlling spectators.
• Net umpire: makes "net" calls (and others the chair delegates), checks the net height and singles sticks, and handles ball changes.
• Match assistant: used when Live Electronic Line Calling replaces line umpires; assists the chair on and off court.
• Referee: final on-site authority on the rules and regulations; supervises play, appoints and replaces officials (or delegates this to a Chief Umpire), conducts the draw, schedules matches and can default a player for cause.
• Chief umpire: recruits, assigns and evaluates chair and line umpires where the referee delegates this.

No official may applaud a player.