What is cloud or cloud technology?
It is an interesting question. It is even more amusing to find out that answer for this question. The answers range from being very "clouded" to technically specific.
Some people think cloud is on-line storage. Some people broadened it a bit more and included email service, social media, websites etc. as cloud. While, these are definitely cloud, but cloud is not limited to these alone. It is much broader and deeper and varying than just online storage or email service.
Technically, cloud can be defined as technology paradigm that isolates underlying hardware and operating software from the actual IT service being consumed. In simpler words, the consumer or an organization who uses an IT service, say a big-data science engine, need not worry about what is the server, storage, network, software etc. The consumer gets to use big-data science engine as a service directly.
A simpler analogy could be arrived by taking a case of a company that needs to transport its goods. The company can have own fleet of vehicles vs utilizing a service provider. In case of own fleet, the company should procure the vehicles, employ drivers, maintain vehicles, fill fuel etc. On other hand, they can hire a transportation provider’s service and pay per trip basis. In case of the latter option, the organization has to just pay the required fee and service provider would take care of the fleet, driving, maintenance etc. The latter option is analogous to cloud service.
Perhaps, it would make it much easier to relate if traditional on-premise IT infrastructure is explained. To build a big-data science engine, following is set up. A server needs to be procured, then network cabling is setup to connect to place the server in data-center network, storage needs to be provisioned, required software needs to be installed and then the application is made available to the user.
In case of a cloud service provider, all of the setup is taken care by the service provider and end user can straight away start using the service (big-data science engine in this case). The service provider would charge based on the time the service used, transactions processed, processing capacity utilized etc. or combination of these. The consumer can utilize as little they need and only for the duration they need as against the hardware and software assets they procure in traditional on-premise infrastructure.
Cloud service providers achieve better economics by pooling underlying hardware, software licenses, large scale IT expert pool. Say, a computing capacity released by one customer can be allocated to another customer immediately by cloud service provider unlike traditional on-premise systems, where it takes much longer to reallocate the capacity.
Going back to our transport fleet analogy, let us take a scenario where the company needs to send out 4 times their yearly average shipments in one particular month of the year due to seasonal demand. If the company were to operate its own fleet, then they would have had to maintain much larger than fleet than average utilization. There would be significant excess capacity during normal months than needed and the added cost. In case of transport providers, they can maintain the average requirement of the fleet for this company. And during the peak load month, they can get the excess fleet from their floating fleet. This floating fleet may be shared across their customers thus achieving cost economics.
So far we discussed public cloud model. There are multiple variations from this model. Most noteworthy variation is private cloud model, where in-house IT teams pool the available hardware resources and create virtual machines (compute capacity). This approach provides somewhat better agility in allocation and reallocation of computing capacities compared with traditional on-premise IT infrastructure provisioning.
The new cloud paradigm thinking has brought in a lot of agility and flexibility in the way IT services are consumed. There is a lot of added value in saved cost as well. It is worthwhile to be cloud aware for business owners, functional/technical user and IT experts.