From Halopedia, the Halo wiki
The Type-3 Refraction Dissonance Modifier/Camouflage system bends light around a structure, hiding it via advanced pattern realignment.
The Z-90 Photonic Coalescence Emitter/Aegis fuses particles of light into a powerful barrier. The shield is deployed in front of the player.
The T-27 Responsive Holographic Form Emulator is designed to confuse or distract the enemies' attention.
The M2705 Regenerative Kinetic Dispersal Field heals the user and any surrounding allies.