what is the internet? the internet is made up of millions of separate web pages or sites, located on...
TRANSCRIPT
What is the Internet?
The Internet is made up of millions of separate web pages or sites, located on special computers called "servers" which are connected to each other, to your computer and to tens of millions of other Internet users’ computers all around the world
The Internet is a whole wide world of words, pictures, data, audio and video, which you
can access on your computer.
Internet Travels
You can compare using the Internet to going on a journey, but unlike real travel you don’t actually have to go anywhere. Instead the world comes to you! And these days using the Internet won’t cost you the earth - there are a wide range of plans available to suit every budget.
Birth of the Net The Internet has had a relatively brief, but explosive
history so far. It grew out of an experiment begun in the 1960's by
the U.S. Department of Defense. The DoD wanted to create a computer network that
would continue to function in the event of a disaster, such as a nuclear war. If part of the network were damaged or destroyed, the rest of the system still had to work.
That network was ARPANET, which linked U.S. scientific and academic researchers. It was the forerunner of today's Internet.
History Continues In 1985, the National Science Foundation (NSF)
created NSFNET, a series of networks for research and education communication.
Based on ARPANET protocols, the NSFNET created a national backbone service, provided free to any U.S. research and educational institution.
At the same time, regional networks were created to link individual institutions with the national backbone service.
NSFNET grew rapidly as people discovered its potential, and as new software applications were created to make access easier.
And continues…. Corporations such as Sprint and MCI began to build
their own networks, which they linked to NSFNET. As commercial firms and other regional network providers have taken over the operation of the major Internet arteries, NSF has withdrawn from the backbone business.
NSF also coordinated a service called InterNIC, which registered all addresses on the Internet so that data could be routed to the right system. This service has now been taken over by Network Solutions, Inc., in cooperation with NSF.
And still continues
• 1974 TCP published
• 1978 TCP and IP split
• 1984 DNS introduced
• 1989 Number of hosts breaks 100,000
• 1991 World Wide Web launched at CERN
Internet Anatomy Even though the Internet is a global network, in many
ways, it resembles a small town, with similar services. Let's say you want to send or receive your mail. The Internet
has electronic post offices. There are online libraries you can use any time of the day or
night, with millions of books and periodicals with unlimited browsing.
Chat rooms are the Internet equivalent of 24-hour coffee shops, with people eager to gab anytime you want.
With the explosive growth of the World Wide Web, you can shop, order a pizza, preview a movie, and listen to radio stations from around the world. All of these represent different ways of using the Internet.
World Wide Web The World Wide Web, the graphical
portion of the Internet, is the most popular part of the Internet by far.
The Web physically consists of your personal computer, web browser software, a connection to an Internet service provider, computers called servers that host digital data and routers and switches to direct the flow of information.
WWW The Web is known as a client-server
system. Your computer is the client; the remote computers that store electronic files are the servers.
Let's say you want to pay a visit to the Louvre museum website. First you enter the address or URL of the website in your web browser. Then your browser requests the web page from the web server that hosts the Louvre's site. The Louvre's server sends the data over the Internet to your computer. Your web browser interprets the data, displaying it on your computer screen.
Hypertext
The "glue" that holds the Web together is called hypertext and hyperlinks. This feature allow electronic files on the Web to be linked so you can easily jump between them. On the Web, you navigate through pages of information based on what interests you at that particular moment, commonly known as browsing or surfing the Net.
Web Pages
A web page is an electronic document written in a computer language called HTML. Each web page has a unique address, called a URL, which identifies its location on the network. A website has one or more related web pages, depending on how it's designed. Web pages on a site are linked together through a system of hyperlinks, enabling you to jump between them by clicking on a link. On the Web, you navigate through pages of information according to your interests.
To send e-mail, you need a connection to the Internet and access to a mail server which can forward your mail. The standard protocol used for sending Internet e-mail is called SMTP, for Simple Mail Transfer Protocol. It works in conjunction with POP servers. POP stands for Post Office Protocol.
E-mail continues
When you send an e-mail message, your computer forwards it to an SMTP server. The server looks at the e-mail address (like the address on an envelope), then forwards on it to the recipient's mail server. When the message is received at the destination mail server, it is stored until the addressee retrieves it. account.
Newsgroups
Newsgroups have been around almost since the dawn of the Internet, enabling scientists to post questions (and answers) to other scientists. Today, newsgroups resemble virtual coffee houses, where people get together to discuss subjects of mutual interest. Except with newsgroups, the communication is written, not verbal. Newsgroups revolve around specific topics. You can read what others have written and
then post your own comments.
Newsgroups ContinuesFirst you will need a newsreader program. Both Netscape Navigator and Internet Explorer have built-in newsreader programs.
Next, determine which newsgroups interest you and subscribe to them. Because of the sheer volume of newsgroups available on the Internet, only subscribe to those that really interest you.
Keep in mind that newsgroups used to be the only way to have so-called threaded discussions, where related messages are grouped together. Today, many websites have discussion groups right on the site. When you are looking for a discussion to join, don't forget to look at websites as well as newsgroups.
Searching
With hundreds of millions of web pages online, you could spend a lifetime surfing the Web, following links from one page to another. One of the biggest complaints we hear concerns the difficulty of finding targeted information. Fortunately, a number of free online resources can help with the hunt.
You've probably heard of Yahoo!, Excite, AltaVista and other so-called Internet search engines. There are literally dozens of these tools to help you locate what you're looking for.
Searching some moreSearch engines breakdown into two categories--directories and indexes. Directories, such as Yahoo!, are good at identifying general information.
But let's say you want more specific information, such as biographical information about Leonardo da Vinci.
Web indexes are the way to go, because they search all the contents of a website. Indexes use software programs called spiders or robots that scour the Internet, analyzing millions of web pages and newsgroup postings, indexing all of the words.
DownloadingWith the World Wide Web, downloading files is as simple as clicking your mouse.
Typically, downloading refers to the method by which you access digital information from a remote computer. As it turns out, almost everything you do on the Web is some form of downloading. For instance, when you access a web page, you are actually downloading the page text and all the associated graphics from a web server.
Your web browser looks at the file extension (the letters following the "."). If it recognizes this type of file, it will display it. If it doesn't recognize it, it will ask you if you want to configure a viewer (tell the browser which software program to use to view the file). You also have an option to save the file to your hard drive.
ConferencingWith the Internet, you can see, hear, talk to, and work with people in different locations around the world, without the expense of travel. One of the most compelling features of the Internet may well be the ability to communicate inexpensively in real time, via desktop computers.
Conferencing can take many forms, such as videoconferencing, audio conferencing, multimedia conferencing, screen-sharing, and, to a lesser extent, what is referred to in Web parlance as chat. The cost of implementing these types of systems can run less than US $100 per computer and are available for Windows, MacIntosh, Linux and UNIX operating systems.
Internet Telephony
With the deregulation of the communications industry, the price of phone calls has plummeted in recent years. But even at these reduced rates, monthly charges can really added up for chatty folks. A new technology, Internet telephony, virtually eliminates long distances charges, allowing you to call almost anywhere in the world for the price of a local call. If you have flat-rate Internet access, you can't beat the price--it's practically free!
Developing a Web Site
Developing an effective website requires thoughtful planning.
There are six basic stages: planning, content development, graphic design, programming, marketing and promotion, and maintenance. Depending on your areas of expertise, you may need assistance on some or all phases of your project.
Internet Now When the World Wide Web began in 1990, few
suspected how successful it would become. There are now millions of websites with over one billion
web pages. But as most people are well aware, the Web can be
painfully slow. Most people connect to the Internet using modems and
telephone lines. Because the data-carrying capacity of telephone lines,
known as bandwidth, is low, receiving electronic data can take a long time. New technology promises to addresses this problem.
And the Future Connecting to the Internet using fiber optic lines and via
cable TV will increase bandwidth dramatically, making the Web more powerful.
Expect to see an explosion of e-commerce, collaborative projects, videoconferencing and virtual environments. Many of these applications are already in use in some form, or are under development.
The incubator for some of the emerging technologies that will shape the future is known as Internet2. Formed in 1996 and administered by the University Corporation for Advanced Internet Development (UCAID), Internet2 is a partnership of universities, corporations and government agencies.
Internet2 The project's goals are to create new applications that
can't run over the existing Internet and to develop the infrastructure that supports those applications.
Internet2 is a not a single network, but a consortium of hundreds of high-speed networks linked by fiber optic backbones that span the U.S.
It transmits data at speeds up to 2.4 gigabits per second-45,000 times faster than a 56 K modem, allowing scientists to test their laboratory discoveries in the real world.
Internet: the next generation The next-generation network went online in February,
1999, linking a number of universities around the world. It should be available for commercial use in a few years.
Then, get ready for 21st century services like interactive television, virtual 3-D videoconferencing, movies-on-demand, and much more.
High-speed networks will make it possible for professionals around the world to work in ways never before possible. For instance, scientists around the world can share specialized equipment like electron microscopes.
An example of what is to come NASA has developed a Virtual Collaborative Clinic that
connects medical facilities around the U.S., allowing doctors to manipulate high-resolution, 3-D images of MRI scans and other medical imaging.
Not only can doctors consult and diagnose, but they can simulate surgery by using a "CyberScalpel." Virtual surgery will give surgeons an opportunity to prepare before ever entering the operating room, reducing the time required for the actual procedure. Using this kind of virtual technology, local hospitals will be able to access resources and skills only available at larger institutions.
NASA plans to use the technology to provide remote health care to astronauts on extended space journeys.