As we saw in our definitions, the Internet is a network of networks
The places on the Internet that serve as the exchange points for the data are calls hosts. An Internet host is a computer on the Internet that exchanges data--whether it is email, Web server traffic, or streaming multimedia--with other hosts on the Internet.
The Domain Name System (DNS) is the means by which Internet computer hosts are organized on the Internet. Each Internet host gets a unique number. This number is the hosts IP (Internet Protocol) address. For example, www.uwm.edu has an IP address of 188.8.131.52. Now this is fine for computers, but these numbers are hard to memorize--it is longer than a phone number. So the DNS maps a unique name, like www.uwm.edu, to its actual IP address. The Internet uses the number; humans can use the name.
The computer host name www.uwm.edu has actually three parts to it. The rightmost part, edu, is called the top-level domain (TLD) name. There are just a limited number of top-level domain names in the whole world, a number kept deliberately low (although it is now over 100) so that it is easy to look up the IP addresses quickly through the DNS.
To the left of the TLD, we have uwm, a second level domain (SLD) name chosen by UWM to distinguish itself from all the other second level domain names in the edu TLD. There could be another domain name uwm.com, but that is different from uwm.edu, even though they SLD's are the same, because the TLD's are different.
Other institutions within the edu TLD choose different SLD name. Thus there is msoe.edu and mu.edu, and there is no confusion among them, even though they share the same TLD.
You can use a "whois" service to find out the organization that owns a domain name and a "nslookup" service to get the IP address of an Internet host. Look in the "Information/Utilities/Use via Web" section of the Internet Tools Summary for links to Web-based versions of these tools.
Next, to the left of the second-level domain, we have www, a name that the folks at uwm.edu named their Web server (a computer host) for their organization. To the left of uwm.edu, the organization uwm.edu could have longer domain names this: www.sois.uwm.edu or www.panthermail.uwm.edu.
So, in sum, we have the Domain Name System to give us a way to create unique names for any computer on the Internet. The DNS takes care of translating the name of a computer host into an IP address so that other computer hosts on the Internet can exchange data with it.
As we saw in our definitions, the World Wide Web is a client-server application that uses the Internet for data communication.
The World Wide Web is not the only client-server application that uses the Internet for data communication. In fact, there are many other Internet Tools such as gopher, ftp, telnet, as well as communication applications like ICQ and IRC.
But the Web has been so pervasive in use, the scheme for addressing particular documents on the Web has come to represent in the popular mind an "Internet address."
A Web addresses is called a Uniform Resource Locator (URL, pronounced "you ARE ell").
You can look at these examples of URLs. The URL is a good way to describe resources that a Web browser accesses. As such, it has become a kind of defacto standard for identifying the address of any Internet Resource, even if it is not one that you find using a Web browser only, such as ftp documents or gopher sites.
You'll see URLs all over. However, remember the correct syntax for a URL includes the protocol in front of it.
For example, here is is a URL of correct syntax:
You might see host names used to publicize a Web site. For example, you might see the red, white, and blue trucks of the United States Postals Service (USPS) sporting this:
It is not syntactically correct. It is missing the protocol name in the front (http) and the : and the two slashes //. You probably can figure all that out, and if you are doing Web promotion, certainly you want to promote the name of your site in the most easy-to-remember way. But just remember, www.usps.gov is not a URL.www.usps.gov
Many things: news, sports, weather, reference information, old-time victrola music, the periodic table of the elements, Encyclopedia Britannica, 10,000 operatic arias, 10,000 maniacs, 12,000 free ebooks, The Smithsonian Institution, Trinidad & Tabago, Cats, software, Wells Fargo, The American Rhododendron Society, The US government, Tori, ABBA, and more.
Yup. Internet content includes lies, truths, half-truths, deception, goodness, evil, tons of mediocrity, excellence, governments, businesses, and expressions of just about human thought, emotion, trivia, and chaos.
The biggest mistake you can make is to look at the Internet's content as one, unified whole. There is no one organization or person overseeing the editing of all Internet information. But this doesn't mean that the Internet doesn't contain some well-edited content (such as traditional news organizations and official sites of colleges, research labs, magazines, etc.).
Do not think of the Internet's content as a library. The Internet is not a library. The Internet is more like a dynamic, diverse city, containing all kinds of human intelligence and stupidity, humor and anger, danger and safety. Conduct yourself on the Internet as you would in a large city--you would not believe everything you hear, nor would you do business, make friends, or associate with anyone you just happen to come across.
Be very careful to avoid the kind of sensationalism many journalists love to do with the Internet. If a murderer stalked his victim using email, the headline reads "Murder on the Internet." That same stalker may have also used a telephone, an automobile, the Interstate highway system, and tennis shoes to commit his crime, yet these objects are not as easily maligned. In truth, no one has been murdered on the Internet.
Some journalists, academics, and other people also like to locate the most lurid, stupid, or inane sites (of which, there are many) on the Internet and thereby imply with smug satisfaction that the entire Internet's content is likewise lurid, stupid, or inane. I think people who do this are very frightened at how much the Internet has become such a pervasive information source--and an authoritative one--for many things. Those people whose power is in off-line content certainly don't want to lose their influence to Internet-based activities.
Look in the "Current Internet Conditions" section at the top of the Internet Tools Summary for a link to some sites that show the state of Internet data traffic.
No, neither the Internet nor World Wide Web is like to "crash" in some single, catastrophic event (I hope). There is a great deal of redundancy and diversity in the systems and networks that make up the Internet and Web, so it is very unlikely that all these systems (or a major portion) would fail at the same time.
No, the Internet is not a 100% stable, safe, secure, or reliable means of transmitting or receiving information. Computer hardware, software, networks, content, and humans often fail, cutting off your ability to access Internet content. Email gets lost, garbled, or is "bounced" (returned to sender) because the recipient's host is unavailable or the email account is full. (There are hundreds of other reasons why someone might not receive and read the email you sent to him or her.)
Web pages can become unavailable for many reasons. The Web server may not be operating temporarily (or permanently) or the network into the server could be too crowded with traffic. People who maintain Web sites regularly change URLs, change the location of pages, remove pages, rename pages, re-design the entire site, rename pages again, or rename the server without any forwarding information.
Internet content changes each second. Web servers come online. Web servers go offline. Web pages come into existence. Web pages go out of existence. People add information to Web sites, contribute to mailing lists, participate in Web-based discussions. Web developers create Web pages, change Web pages, remove them, rename them, and then rename them yet again.
No, the Internet is just like life.
A simplistic desire to see the Internet as a single, simple, uniform, constant entity is the wrong attitude. Likewise, the other extreme view of the Internet as only a lurid, virus-infested swamp of inane or dangerous activity is not accurate. The Internet is a place for human communication founded upon computer-mediated communication systems. As such, the Internet brings together the somewhat chaotic expressions of human beings with the exacting fussiness of computer systems.
You can cope, however, if you recognize the Internet's diversity (keeping in mind the Internet-as-city analogy) and build your Internet information literacy.
When you come across information on the Internet, ask yourself:
Many people exploit the Internet's communication capabilities to spread lies and engage in fraud. Be very skeptical of unusual information (too good to be true or too disturbing to ignore) and do not give out information about yourself or financial accounts to unknown or untrusted people or sites.
A good source of information for debunking Internet-based hoaxes is Hoaxbusters and Scambusters.
The Internet is also a conduit for false stores called urban legends that have previously proliferated for hundreds of years by word-of-mouth, paper, and later by mechanical (photocopiers) and electronic means (telephone, fax machines). The Internet plays a leading role in debunking these myths. So if you hear a story that seems too good to be true or somehow suspect, check out the Truth or Fiction site or the Urban Legends pages.
Another type of unwanted Net content is a computer virus. Often these viruses are spread through email. Read this article about "How Computer Viruses Work," from HowStuffWorks.com and do your best to use virus protection software on your PC and avoid opening email messages (or attachments) from people you do not know or trust.
Also, be aware of public WiFi network dangers. I use a set of Surf Links (see about) for browsing Web sites on public WiFi networks.
You can also look at resources for exploring and browsing the Internet.
Describe the what you have found on the Internet. What do you still want to find?