Cloud generally refers to the use of a network of remote servers hosted on the Internet. This allows users to store and access data such as photographs, documents and music using devices including mobile phones, tablets and computers.
Nadella said: "Simply put, our vision is to deliver the best cloud-connected experience on every device."
Microsoft on Thursday unveiled its Office suite for Apple's iPad, hinting at the firm's growing stress on mobile apps.
Microsoft said Office 365 subscribers can add iPad as one of the chosen devices in their subscription benefits and can create and edit documents with Word, PowerPoint and Excel. The apps are available as free downloads from Apple's iTunes App Store.
Nadella said the world is "exploding" with device types, shapes, sizes and form factors and will continue to do so. Devices extend abilities in ways that are uniquely suited to task, context and occasion.
"As long as human curiosity and ambition drive us to create new things, capture moments and collaborate to get things done, we should expect the world of devices to follow suit. In fact, that's what drives our ongoing evolution of Windows," the Hyderabad-born techie said.
The cloud is how a phone, a tablet, a computer and a TV - all get on the same page and enable movement between them without extra effort, he added."The cloud is how a device becomes your device. And the cloud is how your device becomes part of your life, by connecting to all the people, information and experiences that matter to you. And for us, the cloud is also how a tablet becomes a useful and powerful tool," Nadella said.