Ok bees...I'm just starting a new job and getting enrolled in a new health plan, etc.... Can someone explain the difference between an HSA and an FSA? As far as I can tell the main difference is that funds in the HSA never expire. Is there an advantage in enrolling in one vs. the other? (My employer offers both options).

I've always just cobbled together various PT-jobs and paid for health expenses OOP...this is all new to me!!

Any advice/input is appreciated, thanks!