The other day I was asked "What is cloud computing." I looked at it as being a concept that you just know like "time." How many of you can give a complete definition of time without referencing a dictionary? A short version of what I told him is that if some one uses cloud services it means they use computers that are some where else owned by some one else.
But I heard some one give a nice analogy explaining cloud computing. So I am taking it as my own.
I live in a house. Imagine for a moment that I decided to power the house by means of my own. I'd have to have a generator of some type constructed (solar batteries, hydroelectric generator, windmill, nuclear, what ever). That generator would require some type of maintenance. If I needed more power than the generator could produced then I would either need to suffer through having sufficient power or I would need to add more generators. If I add more generators and then find that many times I don't need them then I have the extra expense of maintaining these extra generators. I don't know anything about maintaining such equipment myself. So I'd either have to be trained in doing so in addition to the other tasks I do around the house or would need to pay some one else to take care of this.
Thankfully that's not how things work at my house. My neighbors and I get our electricity from our power company. I have no idea where it is generated or how it is generated. I honestly don't care as long as it makes it's way to me. If I need to use more electricity than usual in a month it's available. If I use less than I can do so and pay less. I don't have to worry about the space constraints for a generator or hiring staff to take care of it. I just pay for the electricity I need and go on about my business.
That's pretty much how Cloud Computing works in a nutshell. Only instead of purchasing electricity you are purchasing computing and/or storage. You may not know where the computer is actually located. On some plans if more computational power is needed the number of machines allocated can automatically increase for as long as needed and then decrease when no longer needed. There's no need to worry about maintaining the machines as the company that sold them will take care of that.