These bearings come in internal and external types. Internal bearings have an outer-ring ball groove ground to a spherical surface. This surface makes these auto bearings insensitive to misalignment, but increases raceway contact stresses, which cuts load capacity.
Externally self-aligning bearings have a spherical surface on the outside of the outer ring, which matches a concave spherical housing. External bearings have better load capacity than internal, but demand greater radial space.