Although cloud computing drastically changes some of the traditional norms associated with information technology, most of the underlying technology and security basics remain the same. The below listed NIST definition is the most commonly and globally utilized, cited by professionals and others alike to clarify what the term “cloud” means.
“Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.” – NIST Definition of Cloud Computing
Source: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-145.pdf
To quote Maya Angelou –
“I have great respect for the past. If you don’t know where you’ve come from, you don’t know where you’re going.”
So, let’s explore how IT evolved into cloud computing.
The first age of computing was the 1970s, when the focus was on big infrastructure—mainframes, big point-to-point networks, centralized databases, and big batch jobs. Toward the end of the decade, terminals evolved into personal computers, while networks went from hierarchical to decentralized, with a broader, generally more numerous collection of servers, and storage scattered throughout an organization. This period also saw the rise of databases, which were important to business because they held the business data that was manipulated by the applications in the execution of business processes. This data was typically structured, hierarchical, and tightly linked to the associated business processes.
The second age heralded the rise of the internet—Sun, Cisco, Mosaic (which became Netscape), Web 1.0, eBay, Yahoo, baby.com, and the first internet bubble. The biggest technical contribution of the second age was in the network itself. In being forced to deal with the possibility of massive network failures caused by a nuclear attack, researchers endowed their invention with the ability to self-organize, to seek out alternate routes for traffic, and to adapt to all sorts of unforeseen circumstances. The single point of failure that was typical of mainframe-inspired networks was removed and in one fell swoop the biggest technological barrier to scaling was eliminated.
The third age saw the explosion of data and wireless mobility. Email and social media made unstructured data more important than structured data. Early in the second age, Yahoo started “indexing the internet,” which for some time was mostly manually constructed. While this was sufficient for a while, it soon became apparent that manually built indices could never keep up with the growth of the internet itself. Several other indexing efforts began—including AltaVista, Google, and others—but it was Google where everything came together. Google realized that the precipitous drop in the cost of storage and rise in the importance of unstructured data had simultaneously reduced the business effectiveness of highly structured databases and associated structured query languages. They revolutionized internet search by automating it with map-reduce, no-SQL, and AppEngine, an early platform as a service. Amazon Web Services innovated business infrastructure using “brutal standardization” and API-driven infrastructure as a service. Salesforce.com rode their Force.com PaaS to becoming the world’s first billion-dollar software as a service company. With these business models as proof points, cloud computing was born as an economic model.