The Covenant Army comprises the majority of the Covenant's ground-based infantry and units; its purpose is to invade enemy positions and hold them after annexation as a means of military defence and uses a variety of equipment and weaponry. Primarily led by the Jiralhanae (and formerly by the Sangheili, including the former Arbiters), the army is comprised of most of the military-service races who act as infantry, or, in the case of Mgalekgolo, as mobile weapon platforms and shock troops.
Because San 'Shyuum do not hold military ranks, no San 'Shyuum is truly a "member" of the army; instead, they command its Jiralhanae leaders as religious and political figureheads, leaving the Jiralhanae commanders to accomplish military objectives. Huragok, as primarily non-combatants, are also exempt from the army.
The Covenant ground forces are mainly composed of Grunts and Jackals, who are used primarily as cannon fodder and scouts, respectively. Grunt and Jackal footsoldiers are usually weaker than UNSC ground forces; however the other species, though less in number, fare much better than the UNSC in combat situations. The presence of a SPARTAN, however, may drastically improve the odds for the UNSC.
Sangheili Minors: most often seen leading lances of Unggoy and Kig-Yar, the Minor is the lowest-ranking and most common of the Elite ranks.
Sangheili Majors: some of the most reliable and trusted soldiers in the Covenant Army, the Elite Major will often lead lances of Elite Minors into battle. They also serve as first mates aboard starships, one-time stealth warriors and pilots.
Unggoy Lance: Grunts are the most common of all Covenant infantry and while their battle proficiency varies greatly, they are usually used merely as cannon-fodder.
Kig-Yar Minor: deployed as specialists such as scouts and snipers, the Kig-Yar do not hold to the Covenant faith and are instead contracting mercenaries.
Kig-Yar Commando: another, more robust species of Kig-Yar (known to the UNSC as Skirmishers) are used as commandos and special operatives. These Skirmishers are usually far taller than the average human, though speed and agility are still their greatest strengths.
Ghost: one of the most common of all Covenant ground assets, the Ghost is fast and highly maneuverable.
Wraith: though less prolific than the Ghost the Wraith fills the mortar/tank categories.
Scarab: initially designed as a mining vehicle, the Covenant later weaponized the Scarab, turning it into an ultra-heavy assault platform.
An energy dagger is the primary supplemental close quarters weapon for Sangheili in the field.
Jiralhanae Minor: while primitive and uncivilized, the Brutes are unbelievably strong and their carnivorous nature makes them daunting psychological foes.
Jiralhanae Chieftain: the Brute Chieftain is one of the most fearsome foes to encounter on the battlefield; especially when wearing power-armor and wielding a Gravity Hammer.