Client/Server Computing: Centralized Applications and Storage
In client/server model all the software applications, data, and the control resided on huge mainframe computers, known as servers.
If a user wanted to access specific data or run a program, he had to connect to the mainframe, gain appropriate access, and then do his business.
Users connected to the server via a computer terminal, called a workstation or client.
Drawbacks in client /server Model
Even on a mainframe computer, processing power is limited.
Access was not immediate nor could two users access the same data at the same time. When multiple people are sharing a single computer, you have to wait for your turn.
There isn’t always immediate access in a client/server environment.
So the client/server model, while providing similar centralized storage, differed from cloud computing in that it did not have a user-centric focus. It was not a user-enabling environment.
Peer-to-Peer Computing: Sharing Resources
P2P computing defines a network architecture in which each computer has equivalent capabilities and responsibilities. In the P2P environment, every computer is a client and a server; there are no masters and slaves. P2P enables direct exchange of resources and services. There is no need for a central server, because any computer can function in that capacity when called on to do so. P2P was a decentralizing concept. Control is decentralized, with all computers functioning as equals. Content is also dispersed among the various peer computers.
Distributed Computing: Providing More Computing Power
One of the subsets of the P2P model. Distributed computing, where idle PCs across a network or Internet are tapped to provide computing power for large, processor-intensive projects.
Collaborative Computing: Working as a Group
Multiple users to work simultaneously on the same computer-based project called collaborative computing. The goal was to enable multiple users to collaborate on group projects online, in real time. To collaborate on any project, users must first be able to talk to one another. Most collaboration systems offer the complete range of audio/video options, for full-featured multiple-user video conferencing. In addition, users must be able to share files and have multiple users work on the same document simultaneously. Real-time white boarding is also common, especially in corporate and education environments.
Cloud Computing: The Next Step in Collaboration
With the growth of the Internet, there was no need to limit group collaboration to a single enterprise’s network environment. Users from multiple locations within a corporation, and from multiple organizations, desired to collaborate on projects that crossed company and geographic boundaries. To do this, projects had to be housed in the “cloud” of the Internet, and accessed from any Internet-enabled location.