What is the difference between a hybrid and a plug-in hybrid in the Audi A8?

I am considering buying an Audi A8 but I am confused about the difference between a hybrid and a plug-in hybrid. Can someone please explain it to me?

The main difference is that a hybrid car runs on a combination of a gasoline engine and an electric motor, while a plug-in hybrid has a larger battery and can be plugged in to charge. This gives the plug-in hybrid a longer electric-only range and better fuel efficiency in general.

One way to think about it is that a hybrid car is like a regular car with an electric boost, while a plug-in hybrid is more like an electric car with a gasoline backup.

In the Audi A8 specifically, the hybrid model has an electric motor that assists the gasoline engine in certain driving situations, while the plug-in hybrid has a larger battery that gives it a longer electric-only range. Both models still have a gasoline engine as the primary power source.