In Homeworld and Homeworld: Cataclysm it is possible to select groups of ships and order them to fly in different Formations. Each comes with different strengths and weaknesses in various situations, affecting not only the positioning of the ships but also how strike craft fly when attacking. If a ship of a formation is destroyed, the remainders shuffle around to keep the shape as "pure" and unbroken as possible. Note, if ships with different movement speeds are grouped together when selecting the formations the entire group will move at the speed of the slowest ship.
During Homeworld 2, when Strike Craft were converted into squads instead of individual ships the tactical formations were simplified into Aggressive, Neutral and Defensive.
Also known as Military Parade, this is the elegant lined-up formation that the fleet starts and ends long-range hyperspace jumps with. It is also closely tied with the Mothership; if the Mothership moves the rest of the fleet moves with it keeping in the Parade formation, without having to select them to move as well. It is extremely unsuitable for combat and is used more for show and coordinating jumps, but you are able to select it in other situations if you so choose.
Ships flying in the X formation literally form a giant X through space. The squad aims itself at targets based on how the ship at the center of the X would fly. This gives a relative balance of attack and defense, and Strike Craft attack in strafing runs. Ships on the outer tips of the X may have trouble getting into range of targets.
Claw formation is a highly aggressive form of the X formation; the outer arms of the X curve forward so that the squadron effectively wraps around the edges of a target, firing heavily as they go. Strike Craft attack in strafing runs. Ships on the outer tips of the claw are very vulnerable to enemy fire and can be expected to take regular losses.
More suitable for capital ships, this puts your ships into a 2-D wall formation that is easy to maneuver with the intention of having a large number of weapons firing rapidly on any enemy ship that gets in range. The ships are extremely unlikely to dodge anything so Strike Craft can be expected to take significant losses in this formation; it is not recommended for them. It works quite well for combat capital ships.
The strike craft take positions around a single target ship and hold themselves there in a mini geo-synchronous orbit at almost maximum weapon range. Any move the target ship makes, the strike craft match to keep themselves in relative position. The strike craft fire their weapons at the target ship at the maximum possible rate, and perform almost no evasive maneuvers of any kind so target ships with good anti-strike craft weaponry will inflict heavy losses. This formation is extremely unsuitable against enemy strike craft but can inflict ruinous damage against capital ships. Also, one key note; the strike craft will always position themselves in the shape of a perfect sphere when attacking. If the target ship is extremely long and relatively narrow it is possible for some ships to move outside their weapon range, so this is not recommended for attacking any long, narrow ship larger than a Heavy Cruiser or Dreadnought.