C&C 3 Tiberium Wars: Factions: GDI: Units

Rifle Squad
The Rifle Squad is a squad of 6 people each equipped a sub machine gun. The Rifle Infantry is the most basic infantry unit of GDI forces. When near a civilian building they can take cover, giving them a slight boost in armor. They can also dig in in open terrain (for a cost of 300 credits), fortifying their position.

Rocket Infantry Squad
Rocket infantry squadron members fire rockets at both ground and air targets.  They come in squads of 2, and are effective against both air units and ground vehicles.

Zone Trooper
The Zone Trooper wears a large high tech suit which not only helps protect him from enemy fire and Tiberium infestation but also allows him to fly into the air and become an air unit until he lands where he wishes. He is equipped with a high tech machine gun.

The Engineer is equipped with the knowledge of how to take control over enemy buildings instantly, but is otherwise unarmed, so he needs to be accompanied by other units to protect him on his way. Once he takes control over the enemy building, you gain full control over the features and units of that building. He can also capture the husks of fallen mech units.

Sniper Team
The GDI Sniper team is effective against other infantry, and can kill them at long range. It can also spot targets for Juggernauts, increasing their range.

Commando
The Commando is an elite GDI infantry armed with C-4 and a silenced rifle. He has jet packs that allow him to move quickly across the battlefield.

Grenadier Squad
The Grenadier Squad consists of 4 soldiers, armed with guided grenades, which can clear out garrisoned buildings. The Grenadier squad has the ability to call for transport, and can be upgraded with composite armor.

* All Infantry have the ability to summon a V-35 Ox right from above to carry them wherever they need to go. This is a one-use per-unit feature and costs 500 credits.

MCV
The MCV (Mobile Construction Vehicle) is a slow moving unarmed unit. It needs to be deployed to construct a new base at the desired location. Because it's mobile, you can send it off to an empty space on the land and establish a base there without having the need of any other building of yours near it. It can be ordered to un-deploy to move to another location if needed.

Harvester
The Harvester harvests Tiberium crystals into its four small pipe-shaped silos on its back. One harvester comes with each built refinery. It travels automatically to a Tiberium field and harvests until it's full, then goes back to drop the Tiberium at the refinery before repeating the cycle. Though it is well armored, it is slow, so keeping it protected is important, especially since it is the main and only unit that can generate credits. It is armed with a small machine gun.

Pitbull
The Pitbull is a Jeep-like four wheel vehicle that has very light armor, so it can only sustain a little damage before exploding. A really fast, cheap, light armored, light-armed land vehicle: great for scouting and effective against aircraft.

Predator Tank
The Predator tank doesn't have great armor like the Mammoth, but it has medium armor which allows it to be protected as well as move relatively quickly. It has one cannon on its right side, and can be upgraded with Rail Guns. It is considered to be the basic tank of the GDI forces.

Mammoth Tank
The Mammoth! This tank has superior armor and firepower, but because of that it moves slowly - becoming an easy target for air units. On the other hand, in addition to its two great cannons in front, it has two pods of missile launchers at the side of each barrel which can easily take down enemy soldiers and aircraft. The Mammoth can be upgraded at the Tech Center to have rail guns instead of the front two cannons.

Juggernaut
The Juggernaut is the main artillery unit of the GDI forces. The Juggernaut is a two legged mech with large cannons on its top. It moves slowly, shoots far, and has decent armor. It can bombard targets spotted by a sniper team.

The Rig
The Rig is a truck that can deploy into a Battle Base. When deployed, it has two cannons and repairs nearby vehicles.

VTOL Orca Fighter
The classic Orca has been improved over the years since the last Tiberium war. It still features its air-to-ground rockets, but the new model also has a machine gun mounted under its nose to quickly eliminate infantry.
Each Orca can be upgraded with the ability to "Pulse Scan"; this ability allows the Orcas to detect nearby stealth units using soundwaves.

Firehawk Fast Attack Jet
The Firehawk, as the name states, is a fast attack jet.  It can be used against both ground and air targets, and as such it is an effective companion for Orca Fighters. It can only carry one type of payload at a time.

V-35 Ox VTOL Transport
The VTOL Transport is designed to carry most types of vehicles and infantry squads across the map when called into action.  It is great for quickly transporting troops behind enemy lines. Each one costs 500 per use.