UNITED EARTH FEDERATION (a.k.a UEF)
Units: Low-tech, mostly single purpose units
Shields: Absorb all damage but thus are vulnerable to weapons with area damage when grouped, can be manually recharged
Shield Busting Via: Brute force
Healing: Energy Generators can be upgraded as Healing Towers, Field Engineers and Support Command Units have healing bonuses
Auxilary Transport Method: Afterburn, some units have jump-jets
Economy: Easiest to research economy upgrades, upgradable Research Station Overdrive
Extra Research: Converted to mass via Research Convertor
CYBRAN
Units: Mostly multi-purpose favouring stealth/'hit & run'/martydom
Shields: Drains damage but lets projectile through
Shield Busting Via: Reclaiming
Healing: Upgradable Double Heal Rate for Engineers & Support Command Units & Assault Bots
Auxilary Transport Method: Jump-jets
Economy: Mass conversion at start of game, reclaiming using Mass Extractors & Recycler & Magnetron, Mass Fabricator
Extra Research: Converted to energy via Proto-Brain
ILLUMINATE (a.k.a. Aeon)
Units: High-tech and highly upgradable units that may have activatable 'crossover abilities'
Shields: Drain damage but are also reflective, units have upgradeable health on shields, structures & ACU are upgradable with Energy Sponge
Shield Busting Via: Capturing, anti-shield EMP missile
Healing: Many units have healing auras or can be upgraded to have one
Auxilary Transport Method: Teleport
Economy: Mass Extractor Overdrive, Quantum Energy Sponge on Shields, expanded ACU Resource Allocation
Extra Research: Converted to Rouge Nanites with available Research Station upgrade