How is the organ system different from the organ apparatus?

The words “system” and “apparatus” mean the union of something. The difference is as follows:

A system is a set of organs that differ in their specific function and participate in the same process. An important aspect is that the organs of the system have the same origin.

The apparatus of organs is the association of various organs that are identical in their common function, but they differ in origin. For example, the musculoskeletal system includes a skeleton, which is formed from mainly connective tissue and muscles.