What are the main differences between a-mount and e-mount camera systems in terms of compatibility and lens options?

The main differences between a-mount and e-mount camera systems lie in their compatibility and lens options. A-mount cameras are compatible with A-mount lenses, while e-mount cameras are compatible with e-mount lenses. A-mount lenses can be used on e-mount cameras with an adapter, but e-mount lenses cannot be used on A-mount cameras. E-mount cameras have a wider range of lens options available compared to A-mount cameras.