djjs

This just came under the spotlight when I was looking for replacement parts of both pump and filter.
Noticed there are both one inlet, one outlet and 2 inlet (one smaller than the other) 1 outlet pumps.
What warrants the difference and what is the smaller inlet for? Is it possible to interchange between 2 models? Is it possible to just plug/delete the other inlet?

Same goes with the filter, I've seen one type with dual inlets and dual outlets, the other type being single in and single out. What is the difference and why? (The purpose of dual in/out, e.g. where do they connect, possible modification/retrofit/deletion?)

Thanks a million in advance. I've got plenty of technical questions wanting to discuss with fellow owners/technicians/enthusiasts here.