If you are curious enough, you can find out for yourself, for free:
https://www.drivethrurpg.com/en/product/144651/exemplars-eidolons
But if you’re not, the most obvious differences that come to mind would be: a) Heroes - an altogether different “tier” of being, to which all PCs belong - do damage directly to non-Heroic beings’
Hit Dice, rather than Hit Points; and b) Fray Dice, which are essentially automatic damage that will be inflicted on, again, non-Heroic beings, this time all of them in close proximity, every round, as a kind of “free action” thing,