You might not think about your Google/Nest smart display having an operating system. But it does, and until now it was called Cast OS, which is based on the common computer foundations of Linux.

Now though, change is afoot. Google is quietly upgrading the operating system of the first-generation Nest Hub – that's the one that arrived in 2018 as the Google Home Hub before being renamed. It will switch from Cast OS to Google's own Fuchsia operating system.

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You are unlikely to notice the difference, however, as the user interface will remain the same as before. Instead it is the foundations of the Nest Hub that are changing.

But why, you might well be asking. The truth is, no one is entirely sure. Google has been quietly working on the open-source Fuchsia operating system since at least 2016. It has since been spotted on internal test devices, including Chromebook laptops, and it was once said to be a replacement for Android.

Despite it now being out in the open, Google is continuing to be somewhat vague about what Fuchsia is, and might one day become. The company describes it as a "production-grade operating system that is secure, updatable, inclusive, and pragmatic" – whatever that means.

Petr Hosek, a Google engineer who is the technical lead of the Fuchsia OS toolchain team, tweeted this morning: "You don't ship a new operating system every day, but today is that day." In response to a question on Twitter about the roll-out he added: "We're starting with the first-generation Nest Hub" and linked to this 9to5Google article.

It makes sense for Google's roll-out of Fuchsia to start small, and the Nest Hub feels like a worthy candidate for this first dip of a toe into the waters of an all-new OS. But for now Google users are unlikely to even notice their smart display has had its entire operating system replaced. The first displays to be updated will be those enrolled in Google's Preview Program, and the roll-out is expected to take a few months to complete.

It's a small step for Google, but one will hope will lead to interesting new uses for its Fuchsia OS in the future.