Cartridges: low output vs. high output

Could someone please explain why these variations exist? I have only had high output cartridges. Why is there low output? I recently saw an ad here on Audiogon where the seller stated he wanted to move back to high output…

So, what are the +’s and –‘s of each?

Thank you.

BTW, I have a Sota Star with a SME IV arm and am thinking of upgrading the cartridge.