A very good and intellectual question. There is not much difference between smart and android tv but there are some points that make android TV better.
Smart TV is a television that comes with built-in applications such as Netflix, Amazon Prime, Hotstar, and many more for watching movies.
This TV supports other applications also for performing other tasks like playing games.
But on the other hand, an Android TV supports the android operating system. Android is owned by Google so you can use the play store for downloading apps and games.
Android TV also supports Google Assistant that you can use to give the command to TV for performing any task.
You can also connect the Android TV with other smart devices at home.
Rest other features like Live cast, home cloud, Chromecast technology, live streaming are the same in both smart and Android TV.
Point to be noted-:
In the television industry, Samsung and LG TVs are there which do not support the Android operating system.
In Samsung’s TVs, you will only find the Tizen operating system and on LG’s TV, you will find webOS.
Rest 90 percent of the television companies like Sanyo, Mi, Kodak, Panasonic, TCL, Sony, etc supports Android OS.
Maximum people support Android TV but that does not mean that Samsung and LG TVs are not good.
The Tizen and WebOS also support voice assistants like Alexa and sometimes Google Assistant.
But Android TV has an advantage in that these TVs support google play store.