Inner wheel bearing

If you flip that loose bearing over, that's the side you're seeing down in the hub.
There's a seal pressed in on top of the bearing that's keeping it from falling free. The bearing outer race (the plain 'ring' in the picture) is under the bearing. You'll see it in there when you take the bearing out.

99/100, clean and re-grease (ask for help on this) and you're back on the road with a new seal. That seal will just pry out. When you see the new seal, it'll click.

Wish I'd known, just did this on the Dakota last week, could've documented for you.

DO NOT just smear some grease in there and keep rolling. Clean all the old grease out and read up on packing the bearings.

If they DO truly need replacing, you'll need either a mig welder, or a press and bearing collars, to get that inner race out. If you lay a bead of mig weld on the race (Don't weld it to the hub....) it'll just rattle out when the weld cools. Otherwise, off to the press and/or machine shop.