Best answer: Simply put, Chromecast is the consumer-facing Google branding for its streaming products, sold as standalone dongles or built into smart TVs, connected speakers, smart displays, and Android TV boxes. Google Cast is the media streaming protocol for software developers that want to to add Chromecast compatibility into apps.

Chromecast is for consumers, Google Cast is for developers

Google can be a bit confusing when it comes to branding and rebranding its different products and services. In this instance, the casting technology that developers use is called Google Cast SDK, which allows apps to connect and stream video and audio to Chromecast-enabled TVs, sound systems, or smart displays. These are referred to by Google as Cast-enabled apps and allow audio and video to be streamed over Wi-Fi to any devices connected to a Chromecast or with Chromecast built-in.

When shopping for a smart TV, speakers, or a smart display you'll want to look for "Chromecast built-in" on the box or mentioned somewhere in the product description. That means the device will show up as a casting target in Cast-enabled apps.

What devices are available with Chromecast built-in?

As you'd expect, most Google products that support Google Assistant integration also offer Chromecast capabilities built-in. Aside from the Chromecast and Chromecast Ultra, you can cast audio to Google's smart speakers, the Nest Mini, and Google Home Max or stream audio or video from apps to Google's own smart displays, the Nest Hub and Nest Hub Max.

Many other brands have partnered with Google to include Chromecast capabilities built right into their TV, speaker, or streaming devices. My favorite third-party Chromecast-enabled device is the NVIDIA Shield TV, which also happens to be the best Android TV product on the market. There also a growing number of smart TVs and speakers makers that have Chromecast built-in. However, in my experience, nothing is quite as reliable or full-featured as using a standalone Chromecast, especially if you want to use Google Assistant to cast content to your TV using just your voice.