There are inner and out bearings but there is also what's called a "race" and it can wears out too. That's at the outside edge of the rotor and can be replaced. The inner part of the rotor has a grease seal that goes on after you grease and load the bearing in to the rotor. The inner bearing is larger and round and the outer bearing is smaller and angled. If you have never done it, it can be a bit overwhelming. It is very messy too. Greasing new bearing takes time and effort. Ask around if you know a few guys that work on their own cars. Not many cars have bearing that need to be greased, hub bearing assemblies took that task away when front drive cars became so popular.
2007 XLT Super Cab 2.3 5 Speed Auto 2 WD