Computer data has been stored on many different types of media over the years. In the early days, data was stored on punch cards, then later, floppy discs, to today's panoply of storage choices, including hard drives, flash drives, and optical discs. One of the newer options is called “cloud storage,” which actually stores your data on the web itself.
Technically, the internet is not one place. It's a nearly infinite number of computers and servers. Think of your data as “floating around in cyberspace.” A cloud storage company will have massive databases, and not just one, but several, sometimes spread across the country or even the world. The data, and copies of that data, are stored on more than one of these databases, so that even if a catastrophe strikes one server location, your data is still safe. Note that cloud storage is a place to store your files online, while cloud backup is a service that automatically backs up your hard drive at regular intervals. Business VoIP providers are using cloud storage in new and innovative ways. You can store your voice mail messages in the cloud so that you can check your voice mail on your computer or smartphone, for example.