To understand the main concept of virtualization, we will use a real – life example:
Presume you have four different sized people who want to go to work, you can get each one of them a vehicle that suits his route and size, this is going to cost you much and also each car will be used for a little time and then left parking. What if you put them all in one vehicle each of them with his seat that suits him and in a way or another let each "virtualizes" that the vehicle is all his. He can use the radio, the air condition and everything else in the vehicle.
Well, the second way is surely better as it is cheaper, faster and gets all what the vehicle can provide. This second way is "Virtualization" except that we will replace the four different sized men with four different operating systems that we want to use and the vehicle with a computer that has virtualization environment so each operating system sees the resources which we demonstrated as the radio and the air condition as if they were only for it.
At this point, a question has jumped into your head: How one radio will be used at the same time by four men? Well this what virtualization software does, it manages and organizes this operation. Consider it as a layer that creates four virtual tuners one for each man so when a man changes the station, the "one" radio will use the "one" Antenna to get "different" station that the man will hear on his own "headphone" leaving the other men undisturbed.
Another question: How one antenna will deliver different stations? That's the hardware part of virtualization. Instead of buying four antennas we will use only one but each man will have his own amplifier that will enable him to get the station he tuned to. If not convinced, think of it as one router that serves many users each using the internet in a completely different way.
It may come across your mind that creating the virtual tuners and the headphones is going to cost more; surely you will change your mind when you know that with no virtualization each computer will be using only 10 to 15 percent of its processing capacity and still consuming the same energy as a full used computer.
For normal user, this doesn't mean much but for IT companies and web hosting servers, this means saving millions of dollars. It is enough to know that using virtualization, each 10 up to 20 servers can be replaced with only one server. This not only saves money and time to buy and install servers but also reduces size of data centers where servers are located.
With the ever increase in data stored on web and in data bases, virtualization will be a must in order to contain all data in a reasonable cost. IT giants like Sun, VMware, Microsoft and many got that point and they are competing who can provide the cheapest and fastest virtualization technology.
