What exactly is “the cloud?”

We see the term everywhere, but does it have a specific meaning?
May 31, 2012

Dear Control Engineering: I see references to “the cloud” in many articles, most recently the discussion about water utilities. Does that term have a specific meaning or is it (pun intended) pretty nebulous?

The term cloud computing is used in many ways, but at its most basic, it is the idea of having files and even applications available via the Internet and not necessarily stored on any specific computer. For example, let’s think about this article. At the moment I am writing it using Microsoft Word on my office laptop. If I save the Word file, it will reside on this computer, and only this computer. The Word application also resides there. That doesn’t help you because you can’t see what’s on my computer. (At least I hope not. Although what I’ve been reading about Flame, maybe I shouldn’t be so sure.)

Anyhow, you will read this via the Internet, so I have to move this document to the Internet-based application that supports our Website. The articles on our site do not reside on my computer, nor does the application that manages our content. These exist in the cloud, and I can access them from any computer that has Internet access. Individuals and businesses are now storing every imaginable type of content on the Internet: Music, videos, photos, text files, financial data, you name it, there is an application. Once moved to the cloud, I can access and edit this article from any computer that has Internet access. That computer doesn’t have to have any specialized software or documents because those thing exist on the Internet.

Theoretically, all you need to work in the cloud is a computer with a Web browser. That’s because all the documents and applications are there waiting for you to access them. You don’t need to install a video player program to watch videos on YouTube or Hulu. I don’t need to buy a music player application to listen to Pandora. The videos, songs, and players reside in the cloud, and you won’t have the slightest idea where those servers are located.

Use of the term has expanded to include information accessible through the Internet. In the article to which you refer, the users of the system can access production information and even exercise control functions through the Internet. I suspect they need to have some software resident on individual computers, but this does not necessarily need to be the case. Welcome to the future.

Peter Welander, pwelander@cfemedia.com