Cloud Computing Evolution
                     CLOUD COMPUTING EVOLUTION
Introduction
• Cloud computing is all about renting computing services. This idea first came in the 1950s. 
In making cloud computing what it is today, five technologies played a vital role. 
• These are distributed systems and its peripherals, virtualization, web 2.0, service 
orientation, and utility computing.
Source: www.geeksforgeeks.org
Distributed Systems
• Distributed systems possess characteristics such as scalability, concurrency, continuous 
availability, heterogeneity, and independence in failures. 
• But the main problem with this system was that all the systems were required to be 
present at the same geographical location.
Source: www.geeksforgeeks.org
Mainframe computing
• Mainframes which first came into existence in 1951 are highly powerful and reliable 
computing machines. These are responsible for handling large data such as massive input-
output operations.
Source: www.geeksforgeeks.org
Cluster computing
• In 1980s, cluster computing came as an alternative to mainframe computing. Each 
machine in the cluster was connected to each other by a network with high bandwidth. 
These were way cheaper than those mainframe systems. 
Source: www.geeksforgeeks.org
Grid computing
• In 1990s, the concept of grid computing was introduced. It means that different systems 
were placed at entirely different geographical locations and these all were connected via 
the internet. 
• These systems belonged to different organizations and thus the grid consisted of 
heterogeneous nodes.
Source: www.geeksforgeeks.org
Virtualization
• It was introduced nearly 40 years back. It refers to the process of creating a virtual layer 
over the hardware which allows the user to run multiple instances simultaneously on the 
hardware. It is a key technology used in cloud computing.
Source: www.geeksforgeeks.org
Web 2.0
• It is the interface through which the cloud computing services interact with the clients. It 
is because of Web 2.0 that we have interactive and dynamic web pages. It also increases 
flexibility among web pages. 
Source: www.geeksforgeeks.org
Service orientation
• It acts as a reference model for cloud computing. It supports low-cost, flexible, and 
evolvable applications. Two important concepts were introduced in this computing 
model. 
• These were Quality of Service (QoS) which also includes the SLA (Service Level 
Agreement) and Software as a Service (SaaS).
Source: www.geeksforgeeks.org
Utility computing
• It is a computing model that defines service provisioning techniques for services such as 
compute services along with other major services such as storage, infrastructure, etc 
which are provisioned on a pay-per-use basis.
Source: www.geeksforgeeks.org
Cloud Computing
• In 1999, Salesforce.com started delivering of applications to users using a simple website. 
The applications were delivered to enterprises over the Internet, and this way the dream 
of computing sold as utility were true.
• In 2002, Amazon started Amazon Web Services, providing services like storage, 
computation and even human intelligence. 
• In 2009, Google Apps also started to provide cloud computing enterprise applications.
Source: www.javatpoint.com