"process" vs. "application process"

I can’t find anywhere the distinction between “process” and “application process.”
For example, both of the following two commands give the same result:

tell application "System Events" to get ¬
		name of first application process whose frontmost is true

tell application "System Events" to get ¬
		name of first process whose frontmost is true

In both cases the result is “Script Editor.” Presumably the difference is trivial or moot in these two cases. I think I would get it conceptually if I had a simple example script of their not being interchangeable. … Thanks!

Technically, application process is a sub-class of process. That means that every application process is also a process, but there could be processes that are not application processes.

But in operation, I have never noticed a process that was not an application processs.

tell application "System Events" to get every process whose class is not application process --> {}

Beyond that, the only difference extension made in the application process class is the addition of the application file property. But again, I have yet to observe any application process whose application file property was different from its file property (from process).

-- the obvious whose clause did not work for me
tell application "System Events" to {file, application file} of every application process
tell result to first item = second item --> true

So, while there is a theoretical difference, I have never noticed any operational difference. Maybe it is a pre“Mac OS X thing.