What is the name of Google's smart home device brand?

Google’s smart home device brand is Google Nest.

Google Nest is the umbrella brand for Google’s connected-home products, including smart speakers, displays, thermostats, cameras, doorbells, routers, smoke detectors, and security systems. The brand grew out of Nest Labs, a company founded by former Apple engineers Tony Fadell and Matt Rogers.

Google acquired Nest Labs for $3.2 billion in January 2014. For a period, Nest operated as a relatively independent Google-owned company, while Google separately marketed products such as Google Home and Chromecast. In 2018, Nest was folded into Google’s hardware organization.

At Google I/O in May 2019, Google announced that its home products would be marketed under the Google Nest name. That is why older products can cause confusion: Google Home was the earlier name for the smart-speaker line, while Google Nest became the broader brand. Amazon Echo, Apple HomePod, and Samsung SmartThings are competing products or ecosystems, not Google brands.