Android TV stick is a small, portable streaming device that plugs into a TV's HDMI port to provide smart TV functionality, turning a standard TV into a smart TV. It connects to the internet, granting access to apps and games via the Google Play Store, and often includes a remote with a microphone for Google Assistant voice commands. Key features include high-quality streaming (like 4K and HDR), screen mirroring (using Chromecast), and a compact design for easy portability.