Covenant fleet

The Covenant Fleet is an organization of ships within the Navy of the Covenant Empire. It is unclear exactly how Fleets are organized, or how many Fleets there are, but there are likely dozens, if not hundreds of them. Each Fleet is essentially a self-sustaining armada. Each Fleet is given a unique name with religious connotations similar to how Covenant vessels and colony worlds are named by their beliefs.

Overview
Each fleet is led by a Zealot-grade Elite, though the title of the Elite varies depending on the size and extension of the Fleet itself. A regular, permanent Fleet is commanded by a Supreme Commander whereas a smaller, temporary Task Force is led by a lesser Fleet Master.

Many known fleets seem to consist of around 100 starships of all types and variations, and are led by a prominent Flagship, which could be a Supercarrier, or some other type of large Covenant ship where the Supreme Commander or Fleet Master occupies and spearheads the Fleet. There are usually Capital Ships, such as CCS-class Battlecruisers and Assault Carriers, as well as numerous Frigates and Destroyers that serve as escorts and ensign ships to them. Fleets are sustained and aided by Agricultural Support Ships which are attached to them, providing food and supplies to the other ships in the Fleet.

Each Fleet also appears to have quite a number of combat Legions attached to it as well.

Combined fleets
A Combined Fleet, as its name implies, is possibly made up of smaller Fleets and led by a Supreme Commander, or maybe an Imperial Admiral. These Fleets have larger duties, such as safeguarding and policing entire regions of the Covenant empire on their own. These Fleets can have several hundred ships. High Charity appears to have been guarded by a combined Fleet at all times.