During the Clone Wars, the Grand Army of The Republic struggled to properly classify vessels due to the multiple contradictory systems in place across the galaxy. In an attempt to solve this problem, the Republic commissioned the Anaxis War Collage to create a new system for capital ship classification, leading to the creation of the Anaxes War College System, a system that, while seeing little service in the war it was made for, would later serve countless powers throughout history, becoming the de facto system used across much of the galaxy.

This system only covers what it considers capital ships, vessels greater than 100 meters in length. For craft smaller than this, classification is rather vague, with many other systems often being slotted in to fill the gap.

Corvettes:

Length: 100-200 meters

The smallest vessels considered capital ships, Corvettes often serve a supporting role for larger vessels, protecting them against enemy starfighters and munitions. Rarely having the firepower to challenge larger warships, yet having a low cost, Corvettes are a common sight in the hands of planetary defense forces and even under civilian control compared to larger warships. Due to this, the Rebellion had a large number of Corvettes, being far easier to obtain than even Frigates.

Frigates:

Length: 200-400 meters

Providing far more versatility than a Corvette, yet lacking the power or exorbitant cost of larger Cruisers, Frigates are often used as independent vessels or as escorts for larger warships, having the scale to be well rounded, yet being cheap enough to be expendable in comparison to larger warships. Getting your hands on a Frigate as a civilian or even a minor planetary defense force is a challenge, leaving few in the hands of groups like pirates or Rebels compared to Corvettes. Some Frigates are built along the lines of larger Cruisers, focused on raw firepower and engaging enemy warships. These Light Cruisers often serve as flagships of minor formations, or escorts for convoys or less combat focused ships like carriers.

Cruisers:

Length: 400-600 meters

The smallest vessels commonly seen as significant in major battles, Cruisers often serve as the backbones of fleets, fighting as their mainline vessel and backing up the larger warships when they are available. Only the largest planetary defense forces can afford Cruisers, and they are a rare sight in the hands of Rebels or pirates.

Heavy Cruisers:

Length: 600-1000 meters

Larger even still than Cruisers, Heavy Cruisers sit in an off position: lacking the ubiquity of standard Cruisers, or the power of Destroyers. Due to this, Heavy Cruisers of significant size lost popularity after the Clone Wars, the Empire not needing them with its wealth of Star Destroyers, and smaller powers lacking the resources to build them in numbers.

Destroyers:

Length: 1000-2000 meters

The pinnacle of standard warships, Destroyers, or Star Destroyers, are the largest warships to commonly see service within militaries, larger vessels lacking the practicality of production for widespread use outside of special circumstances. While some Destroyers fill a purely combat role, their size leads to most having additional capabilities of similar importance, such as being mobile bases or large scale carriers.

Battlecruisers:

Length: 2000-5000 meters

Massive vessels, Battlecruisers occasionally serve to provide an additional punch to large fleets, their significant firepower bolstering any force they are in. Battlecruisers are rarely used, with it being more economical to produce smaller warships, while Dreadnoughts are better at providing overwhelming firepower against an opponent.

Dreadnoughts:

Length: Greater than 5000 meters

Behemoths unchallenged by anything but one of their own, Dreadnoughts are strategic assets capable of challenging entire fleets or worlds. While the eras before and after the Empire saw some Dreadnoughts constructed, most were built by the Galactic Empire, its military industrial complex being one of the few large enough to produce such colossal vessels in numbers, and its leadership determined enough to see it happen.