Start here: https://www.android.com/tv/

Android TV boxes are basically the Android version of Fire TV or Apple TV or Roku. Not to be confused with the shitty Android boxes, often pre loaded with Kodi and other shit that will break eventually and otherwise give you hassles with mediocre hardware/customer support.

Only good Android TV box on the market right now is the Nvidia Shield TV (also the best streamer out there, hands down). Nexus Players can be found on ebay for a premium. Xiaomi has a box that would be a slight upgrade from the NP coming out soon^TM. The Forge is shit. All of the Android "TV" boxes you see on amazon are shit and should be avoided.

Fire TVs aren't terrible if you don't want to splurge for a shield or hunt for a NP or wait for the Xiaomi.

Boxes that run Android OS are not the same as boxes that run the Android TV OS. This sub is for boxes that run Android TV.

Typically those boxes that are hacked together to run the Android OS (an operating system designed for touchscreens) are typically just AOSP builds where they install a small group of apps/services that are as questionable as the no-name company that put together the hardware. As if there wasn't enough of an issue with keeping Android devices up to date with security patches, imagine using a device on a really old version of the OS with all the holes wide open, while having software of questionable origin installed on it.

Heck, some of them cost more than an NVIDIA Shield TV, which is just a massive ripoff.

TL;DR TV boxes that run Android are not the same as Android TV boxes

As you are new to this that’s why you need to know the basics of android TV boxes but now it’s well used by everyone. You may like to visit Gostreamer website for enhancing your knowledge on Android box and all the features.