Cloud computing is actually not a new idea!
On a hot day during the summer, you may decide that the heat is too unbearable and some air conditioning is needed. The electricity coming into your home is happily flowing to power all your connected devices, yet suddenly now there is the need for more power to cool down your room. Luckily when you turn on that air conditioner, the power plant that is generating that power is able to send what you need through the electrical grid in your town. This is cloud computing in a simple form.
The power plant and all the wires and transformers are your infrastructure.
The ability to view your power usage, turn off service, and start service is the platform.
The electricity is your software.
Above is a simplistic view of cloud computing but should be easy to relate to:
Look at it this way:
Cloud computing is a system where a business or individual can rent hardware and software without having to maintain or store what they are using. Mainframes and servers take up a lot of space and need a lot to keep them running, why not have someone else handle all that?
For example: When you stream from Netflix, you are paying for access to watch a movie. No longer do you need to store your movies on fragile discs; no longer do you need to blow off the dust or clean off the smudges. Netflix does it all for you so that you can just enjoy the show. Plus that same movie can be viewed by many different people on-demand with Netflix, something your DVD copy could not do.
Webhosting used to mean for a lot of companies that they had to have large server rooms and infrastructure onsite to maintain their websites and databases. This meant that they had to have extra resources on hand at all times in case there was a need, costing money even when not in use. Cloud computing makes it possible to centralize these services and share them more effectively and economically so that when there is a need the service is available and only paid for as needed.
So if we go back to the electricity example, traditional Webhosting is like having your own power plant with extra capacity in case you need it that you have to own and maintain. Cloud computing is like your house being connected to the power grid and only paying for what you need while having the ability to get more without any effort if you need it .