Naval Units:
Orbital Fortress - Very slow move rate, immense firepower, designed to be left in an orbital zone, short move range
Heavy Starcruiser - Capital ship, centerpiece of a fleet, large amount of firepower, capable of mounting lots of weaponry and very effective at planetary bombardment
Starcruiser - Capital ship, the usual heavy ship in a fleet, second only to Heavy Battlecruiser in firepower, capable of mounting lots of weaponry and very effective at planetary bombardment
Warcruiser - Capital ship, focused on attack and speed, capable of mounting lots of weaponry including torpedoes
Heavy Frigate - Capital ship, fills the role of heavy cruiser, moderate firepower, moderate amount of marines, capable of mounting some weaponry, can mount torpedoes
Frigates - Escort vessel, large destroyers, low firepower, mainly designed to shield larger ships, can mount torpedoes, standard commerce raider/patrol craft
Destroyer - Escort vessels, flottillas, very low firepower, mainly designed as a shield, can mount torpedoes, scout ships
Troop ship - Troop carriers, flottillas, no firepower, weak defense, no attachments other than Dropships
Naval Brigades:
Torpedoes - Adds a large amount to attack values, Escorts and Heavy Frigates only
Fighter Wing - Adds moderatley to attack and defense values, Capital Ships Only
Bomber Wing - Adds a large amount to attack values, Capital Ships only
Ramming Prow - Adds moderatley to attack, lowers defense moderatley (Crashing into things at 5,000 MPH isnt exactly good for the ships health), Capital Ships Only
Laser Lance Battery - Adds to attack, high IC cost, requires high technology
Shield Generator - Adds to defense
Heavy Bombardment Battery - Adds to shore bombardment and attack, substantial lowering of speed and moderate lowering of defense (Harder to dodge), Capital Ships Only
Dropships - Adds to shore bombardment, Capitals and Transports only
Marine Brigade - Adds extra attack and defense
Land Units:
Infantry - Bog standard infantry
Air Cavalry - Either Air Mobile in helicopters/VTOL aircraft, or jetpack/winged, vunerable to aircraft, fast move speed
Mechanised - Armoured infantry, either in vehichles or with large bio constructs in the case of some species, same move speed as infantry (Due to heavy armour vehichles), but greater firepower
Marines - Specialised Orbital assault infantry
Plantery Defense Forces - Militia, poor all round, mainly designed to buy time for other units
Fortress Division - Garrison, cant move without strategic redeploy, high defense but weak attack
Battle Titans - Huge IC Cost, Giant Walkers/Bio Constructs, Weapon upgrades
Land Brigades:
Mechanised Brigade - Boosts attack and defense, Infantry and Planetary Defense Forces only
Engineer Brigade - Same as base game, Infantry, PDF, Mech and Garrison only
Artillery - Same as base game, Infantry, PDF, Mech and Garrison only
Special Forces - Boost attack and speed (Better recon), Infantry, Mech, Marine and Air Cav only
Battle Titan Weaponry:
Laser Lance - Better hard attack, lower soft attack
Shields - Better defense
AA Battery - Better air defense and attack
Close Combat Gear - Better hard attack, lower soft attack
Assault Infantry Battalion - Extra Soft attack, adds some softness to otherwise 100% hard Titan, adds extra defense
Air Units:
Planetary Fighters - High Air attack and Defense, useless against naval and ground targets
Planetary Strike Fighters - Medium/High Air attack and Defense, low power against naval and ground targets
Planetary Bombers - Low Air attack and Defense, low/moderate power against naval targets and high power against ground targets
Air Brigades:
Orbital Strike Weaponry - Increase in naval attack, loss of defense and speed (harder to manouver)
Escort Wing - Increase in defense, loss of range
Bunker Busters - Increase in ground attack, loss of defense and speed (harder to manouver)