Cloud computing is using a Web browser and the Internet to access applications (like word processing, a spreadsheet, email), store your data (files, emails, pictures) or use computer resources (Web hosting, blogging, creating a YouTube channel) on someone else’s computers instead of yours.
You have used cloud computing if you have used a webmail product such as Google's Gmail or Microsoft's Hotmail. What makes webmail an example of cloud computing is that the email application and your emails are on a remote computer, not yours. This contrasts with running an email application on your PC, like Microsoft Mail or Outlook, and downloading and storing all of your emails locally.
Not everything you do over the Internet is cloud computing, however. Online shopping and banking, paying your taxes or utilities, listening to music or watching movies or videos are not examples of cloud computing. These are just companies using the Internet to provide services to you.
If you want to distinguish between what is cloud computing and what is not, here’s a good rule of thumb. If your alternative to whatever you are doing on the cloud app is to buy something -- a software program such as Microsoft Word or an external hard disk drive -- or to do something you probably think you could never master -- hosting a website, a blog or a video channel on your own PC -- then you’re using cloud computing.
Like anything you do online, cloud computing is not without its risks and requires appropriate security measures to protect your sensitive data.