Wikia

"First of all, the term 'space transport' refers to any vessel that's bigger than a starfighter and smaller than a capital ship - of course, those boundaries aren't set in durasteel. But for the most part, space transports are defined by their function - moving people or cargo from one location to another. That could be across a space dock or across the galaxy, it all depends on the ship's capabilities and their pilot's intentions."

―Sergeant Riij Brinwell, a Sector Ranger of the Parmic sector.^[src]

A transport was a small or medium sized spacecraft or other such craft commonly used for short cargo (or smuggling) runs that didn't require the use of a bulky freighter. Usually equipped with a hyperdrive, though this was not always the case, transports came in a wide variety of sizes and specifications and were produced by a large number of companies. A good example of such a craft is the Corellian Engineering Corporation YT-1300 light freighter, which could be configured for various goods, Human or otherwise. This class of spacecraft was very easy to modify and adapt, and as such was popular amongst smugglers and pirates.

Although most transports were owned and operated by civilians and the criminal element, some militaries used them for the movement of troops and/or their equipment, such as the Sentinel-class landing craft, by Cygnus Spaceworks, used by the Imperial Navy to swiftly deploy its personnel to planets below.