The following lists commercial Solomani spacecraft common to each technology level.
Small craft are less than 100dt and lack a jump drive.
Anything designed for ferrying passengers and light cargo between ships, normally within a few kilometres of each other. Rarely have life support for more than a few days, and have less than 1km/s delta-v. They are often carried by larger ships.
A small craft designed for ferrying passengers and cargo between a planet and low orbit. Similar to boats, with limited life support but considerably greater delta-v due to the need to reach orbit. Most shuttles have the ability to land on a planet and return to orbit, though this doesn't become possible until TL10+.
A fighter is a small one or two man craft, generally less than 20dt, designed for combat engagements. They have high acceleration and a delta-v in km/s or tens of km/s depending on tech level. A day or two of life support is common, though some can support missions of a week or more. They are heavily armed, often mostly with single shot weapons such as missiles.
Larger than a fighter, but still smaller than 100dt. They have longer life support duration (weeks or months), and are designed for patrolling a star system, requiring a high delta-v and moderate thrust. They normally support up to half a dozen crew, so they can have multiple shifts.
A small civilian craft designed for interplanetary travel within a system. Have weeks or months of life support, and moderate delta-v and thrust. Generally unarmed and lightweight. Some of the larger varieties can be greater than 100dt in size, but they are rare.
A jump capable craft generally up to about 300dt in size. The fact that the crew are also the owners tends to be the main definition of a Free Trader.
A jump capable cargo freighter up to 1,000dt in size.
A jump capable cargo freighter up to 10,000dt in size.
A jump capable cargo freighter up to 30,000dt in size.
A jump capable cargo freighter over 30,000dt in size.
Military terminology has been inherited from the ancient wet navies of various civilisations. The design and use of spacecraft doesn't map one to one to wet navy craft, so though many terms are the same, their meanings are often different.
Tend to be lightly armoured, optimised for long range patrols and prioritising a large delta-v other high thrust. Equipped for long range combat, they make heavy use of missiles with a few long range direct energy weapons. Point defence capability tends to be high
A heavily armed and armoured spacecraft which prioritises thrust over delta-v. They tend to prioritise short term engagements rather than long term patrols.
Designed for use close in to worlds, or escorting transports. They tend to be moderately good at multiple roles, rather than being heavily specialised. They tend to be smaller craft, generally less than a 1000dt.