Air Defense

"This anti-air tower is deadly against flying enemies, but can't target foes on the ground. Place it wisely to cover as much airspace as possible."

Summary
The air defense is a powerful defensive building with a very high damage per second, capable of defending against air based units. It can only target single air troops, shooting them down one by one. It can not harm ground based units.

Defensive
The air defense has an excellent range and a very high dps. As the in game description states, it's best to position them so that they cover as much area as possible. One common strategy is to position them in a wide triangle around the town hall (town hall level 9 only). The air defense is a popular first target for attackers via ground troops as they are the only defensive structure that cannot target them. Make sure they are defended well and they will help to keep the skies clear from rampaging balloons and dragons.

Offensive
The air defense is a natural target to attack first. Clearing them helps pave the way for an air assault. They are easily destroyed by any ground based troop type. Naturally, it is advisable to keep balloons away from an air defense as they are capable of destroying them in one or two hits from a great distance.