This series is not meant to teach you how to use The Cloud or how to get your start-up going on The Cloud. The purpose of this series is to provide a brief overview of some of the typical uses and meanings of The Cloud to help make sense of how it fits into your everyday life.
I'd like to start this series on The Cloud by explaining at a high level how The Cloud was born. I'm only going to deal with the concepts of The Cloud and not on specific milestones and companies that contributed to the birth of The Cloud.
The Data Center
The Data Center can be thought of as the predecessor of The Cloud. I say predecessor because for most The Cloud replaced the traditional data center. But predecessor is really a misnomer because The Cloud couldn't exist with the data center. In fact The Cloud is a series of data centers interconnected with a set of services that abstract interacting with the servers and services running in them. The Cloud is really just a commoditization of the traditional data center.
Running a data center meant that your company had to have more than one core competency. In addition to the core competency of building whatever it is that your company built you also had to have expertise in infrastructure, operations, and network engineering (at a minimum).
Running a data center meant you had to have experts on your payroll that understood server hardware. Running your software and services in a data center meant you either owned the data center yourself or you were renting space in someone else's data center (more likely the case). In either case your primary goal was making sure the servers stayed up and running. Your secondary goal was to try to reduce your capital expense and increase the efficiency of your data center by purchasing less and running more on what you purchased.
IT Operations specializes in the deployment and maintenance of the software and services you run. In the data center world an IT Ops engineer will plan and execute the deployment of software either in the traditional model with a hand-off from software engineering to operations or with the now more common model of DevOps.
The Cloud doesn't totally negate the role of operations but instead augments the software engineers role to also include deployment and maintenance of the software. This is usually done using the Continuous Delivery model of software development.
Running a data center also required your company to have expertise in network engineering. Network engineers are responsible for the communications infrastructure within the data center. They manage how data gets in and out of the data center as well as between servers and services in the data center. They maintain the physical and virtual network infrastructure.
And Then Came The Cloud
As companies focused more and more on the delivery of their own software a market emerged where companies provided the ability for you to run your software and services on their servers and offloading the management your IT infrastructure, operations, and networks to them. Thus The Cloud was born.