What’s the difference between a debt settlement or a pay-off?

I embrace the integrate pick up letters as substantially as longed for to know if we should compensate the solve or compensate the sum amount—>>>(on the budget) how would it demeanour upon my credit report? any inform module help… thanks
Not credit adjudge bills: they have been medical, aged cable, dungeon phones…
*credit adjudge up to fellow as substantially as my automobile note too…