Warship classes

With the prevalence of space combat in the world, there have been methods and systems of categorizing spacecraft. For some reason, these classifications have followed old naval methods, much like the rest of space travel terminology.

Classes

Ships are separated into five main classes, each with an approximate size and role (though these do vary between manufacturers and navies

Corvette, 50-200m, hit-and-run, flanking, picket

Frigate, 250-300m, screening, fire support

Destroyer, 300-500m, fire support, specialized weaponry

Cruiser, 500m-1500m, ship-of-the-line, varied roles

Battleship, 3000m-wherever, heavy firepower, soaking damage

Corvettes are the smallest commonly used class. They serve as mainly support ships, though can be assembled into squads with frigates to preform fast hit-and-run attacks. They're also commonly used as patrol craft.

Frigates serve much the same role, though slightly bigger and more powerful. They carry weapons big enough to take down bigger craft on their own, so they are also deployed into fire support positions.

Destroyers are generally more backline ships, equipped with heavy, long-range weapons. They are often the smallest class to deploy spinal weaponry. A group of destroyers is a formidable threat to lone ships.

Cruisers are the backbone of any fleet. Much cheaper than a battleship, but with enough firepower and durability to hold its own, cruisers make up the bulk of most fleets. They are often adapted to a multitude of roles, from picket ships loaded with point-defense lasers to snipers bristling with railcannons and spinal weapons.

Battleships are expensive, heavy, and slow to accelerate craft. But they also pack a significant punch, and can take one too. A single battleship, with good command, can wipe out a smaller fleet solely because they cannot even get through its shields, let alone the multi-ten-meter armour underneath. They are generally in the same situation as cruisers, though they attract a lot more fire due to their sizeable firepower.

Heavy, light, what does it mean?

These warships are generally divided even further into light, normal, and heavy versions. These just generally denote variants that are smaller or bigger than the normal class, though not enough to warrant different classification. There are also super- and ultraheavy variants, though these are mostly in use for battleships, which have no upper limit to size.
For example, the two Indomitable-class heavy cruisers of the Anakrionian Defense Fleet are classified as such because they are bigger then the fleet's other cruisers, but not enough to be called battleships.

Variations

There are obviously various roles the ships fall into, and can be fitted with different weapons and equipment for. Common variants include missile destroyers, long-range battleships, picket frigates and battlecruisers, which sacrifice protection for speed. For the most part, these are manufactured as is, with little retrofitting potential without having to tear apart large parts of the ship.

Titans, colossi, super battleships?

With the increased number of very big ships, upwards of tens of kilometers like the Titanic Lance, there has been discussion of whether or not a new class of ship should be introduced. Depending on who you ask, the class would be called Titan, Colossus, Super Battleship, Dreadnaught, and a hundred other names. They would start anywhere from five kilometers or twenty, and have either no upper limit, or something massive like fifty kilometers. But as of now, no legislations have been passed, though many people refer to ships like the Titanic Lance with those names.