Space Habitats are artificially constructed orbital habitats, either around a planet or a star. The smallest may be a few tens of metres in size, the largest can span a solar system. Some are free floating, others may be built into or on an asteroid or similar small body.
This category doesn't include habitats built onto a world with appreciable gravity of its own.
These are early habitats, often limited to a few tens of metres in size. They can be little more than cargo canisters strung together and given life support, though can be custom built, or a converted space craft with the engines disabled or removed (or even simply not used).