What is the difference between luminous object and illumines the object?

Answer 1

Luminous objects give off light whereas illuminated objects relfect light, and thus appear to produce light. For example: A lightbulb is luminous because it gives off light whereas the moon is illuminated because it reflects the light of the sun.
A luminous object shines with its own light; it produces its own light, like the sun. An illuminated object is lit by some outside source, like a light bulb or something lit up because your car's headlights fall on it at night, such as your garage door.

Answer 2

Luminous is an adjective, and illumines is a verb. I might refer to the moon as a luminous object, meaning that it is able to reflect light. The sun illumines the moon. In this case, the adjective describes something about the moon, and the verb says something about what the sun is doing.