Microsoft is no longer a ‘devices and services’ company, according to CEO Satya Nadella.

Steve Ballmer’s successor instead sees the tech giant as a "productivity and platform company", it was revealed in an open letter he sent to all full-time employees today.

Nadella, who took over as chief executive in February, wrote a missive to staff describing how he defined Redmond, adding that Ballmer’s devices and services label no longer applied.

He wrote: "While the devices and services description was helpful in starting our transformation, we now need to hone in on our unique strategy.

"At our core, Microsoft is the productivity and platform company for the mobile-first and cloud-first world. We will reinvent productivity to empower every person and every organization on the planet to do more and achieve more."

Going into detail, he said productivity for employees, teams and entire businesses was all connected, just like platforms are for "individuals, IT and developers".

He added: "Productivity for us goes well beyond documents, spreadsheets and slides. We will reinvent productivity for people who are swimming in a growing sea of devices, apps, data and social networks."

The letter makes clear productivity is not restricted to Office, also including recent announcements like Azure ML and Cortana, the voice assistant that can check your emails for you.

Instead of being tied to Windows, platforms also encompasses Microsoft’s new open approach to other operating systems, demonstrated by its release of Office for iPad.

A lot of this was fairly clear from Microsoft’s recent announcements, but it doesn’t hurt to clear up what Microsoft’s core is when it does so much. Besides, Nadella’s message to staff reinforces the theme of his tenure so far: Microsoft is changing.