What is a Computer?
We all know what a computer is, but at the same time most of us do not know what a computer is. We just use computers on a daily basis and know how to use it. But it is not easy to say that we know how it works.
A computer consists of CPU(s), RAM(s), Storage(s), Network device(s).
CPUs are for calculation. For example, if you open up an MS Excel file and run some functions in it, then your file requests CPU resource to perform the task.
Where does the computer store the outcome from the calculation of CPU? It depends on the persistency. If your software program just needs the data temporarily, then your computer chooses RAM over Storage. RAM is faster, but the data will be gone when the computer is switched off. The computer goes with Storage when it needs somewhere persistent to keep the data. Even after switching on and off several times with storage, your data remains. Two type of storage disk are mainly used, one is HDD (hard disk drive) and the other is SSD (solid-state drive). SSD is a newer version of storage drive. It is much faster than HDD, but much more expensive, too.
But these computing components alone are not very useful because computers without them cannot access external information. This is where network came in. Do you think computer was invented for individuals? No, it was invented for wars. Governments wanted to decrypt enemies’ secret and they wanted to improve their missiles’ accuracy. Data, generated from computers, had to be able to transfer via external network, Internet.
What is a Data Center?
After computer was invented for governments, companies also found the value of computer and adopted computers for their business. The industrial value of computer was significant and more companies started setting up their data center. Back then, computers were not used for individual employees, but for companies’ important tasks. Afterwards, more employees could use computers. We call an enterprise computers as a server. In short, a data center is a place where there are stacked-computers connected with each other.
What is Virtualization Technology?
But this primitive data centers soon encountered an issue, which is the under-utilization of resources. Some server computers are too busy and others are almost doing nothing. Even though some server computers were not utilized, more servers had to be added for heavy workload.
For storage, a solution was invented. A storage rack was set out of server computers and it could connect with servers via network devices such as switch.
For others, the advent of virtualization technology redefined data centers. The virtualization splits hardware resources into logical parts. Within a server, you can start multiple operating systems(OS) as if you have many servers because a virtualized OS only has the visibility of given computing resources.
For storage again, virtualization companies even tried to virtualize storage so that storages did not have to come out of servers any more, but they could sit in servers as a cluster and start working as a huge connected storage.
What is Cloud Computing?
What is Cloud Computing then? From business perspective, it is an eCommerce business for data centers. More precisely, cloud providers rent out split computing resources as a single item. It was noticed that virtualized computing resources for better utilization was also good for renting out.
For sure, there are more technical improvements from virtualization to cloud computing. The reason of improvement was that simple, but the impact of cloud computing was not simple at all.