Individual buildings, trees and other sorts of foliage assets (cactii, shrubs, lichen, grasses), animals (dogs to exotic zoo critters) and since in some task cases Trainz supports doing the same thing in multiple ways (i.e. Examples of everyday scenery objects are virtually anything which is not part of a railroad, but includes many assets which indeed are.
KIND Scenery provides the basis for all surveyor-placeable assets covering especially those that have no relationship to rails or railroad assets, and is the class of objects which can individually be laid down, rotated, height adjusted, and if capable, tilted.