What is the difference between the internet, the web and the Grid?
The Internet is a networking infrastructure, which connects millions of computers worldwide. The name comes from the idea of interconnected networks.
When any two computers are connected to the Internet, they can communicate with each other. But being connected is not only a question of cables. To talk to each other computers have to speak the same language, i.e., use the same protocol. The common protocol for the Internet is called Transmission Control Protocol/ Internet Protocol (TCP/IP).
The World Wide Web (WWW), or simply the Web, is an information sharing service built on top of the Internet. But it is not the only one. The Internet (not the web!) is also used for text-based e-mails (SMPT: Simple Mail Transfer Protocol), for file transfer (FTP), remote log-in (Telnet) and so on.
The grid is a service built on top of the Internet, as the web is. The Grid goes one step further. The Grid promises to provide sharing computing power and resources like disk storage, databases and software applications.
While one computer may take days to complete a complex calculation, the Grid will make available hundreds of collaborative computers to get the same result faster and more efficiently. Once connected to the Grid, the user will see it as one large computer system, providing almost infinite computing power.
Facts and fictions about the Grid
Fiction: The Grid will replace the Internet.
Fact: Grid computing, like the World Wide Web, is an application of the Internet. It cannot replace Internet.
Fiction: People will be able to download movies 10,000 times faster using the Grid.
Fact: In order to get such data transfer rates, individuals would have to set-up a dedicated fibre-optic link between home and the source of data 9server). If one is able to do that, he/she can download the movie 10,000 times faster even now, without the Grid! With standard dial-up telephone link or shared broad-band connectivity, such speeds will remain a dream. The Grid cannot change the data transfer rate.
Fiction: The Grid is going to dominate www.
Fact: Today’s grid computing technologies and projects are geared toward research and businesses with highly specific needs, such as vast amounts of data to process and analyze within large, worldwide collaborations, like LHC project of CERN. While other computer users may benefit from grid computing through better weather prediction or more effective medications, they may not be logging onto a computing grid anytime soon.
Middleware is connecting software that allows multiple processes running on one or more computers to interact across a network. It allows communication across heterogeneous platforms.
One of the most popular middleware packages developed is called Globus; it is essentially a software toolkit for making grids. With such middleware, the aim is to couple a wide variety of machines together effectively, including supercomputers, storage systems, data sources and special classes of devices such as scientific instruments and visualization devices.