Natural action and Source

Natural action noun - A process existing in or produced by nature (rather than by the intent of human beings).

Source and natural action are semantically related. In some cases you can replace term "Source" with "Natural action", this terms are similar.

Source noun - (technology) a process by which energy or a substance enters a system.

Natural action and source are semantically related. Sometimes you can use "Natural action" instead a noun "Source".