Section 9.9. Using Today s Internet
9.9. Using Today's InternetIn the past, using the Internet meant keeping track of a collection of commands and ftp sites. You had to keep track of the resources as well as the method of accessing them. Today, almost everything you access on the Internet is web-basedthat is, accessible via a web browser. A web browser is a program, much like any other window-based program, with menu buttons, a control area, and a display area. You type in or select a web address, the browser sends the request to the specified computer on the network (either the local network or the Internet), and displays in the window the information that is returned. I won't go into detail about how to use Netscape, or any other browser, since trying it yourself is the best way to learn about web browsing. In general, all browsers have a place to type in a web address, a way to view your browser's history (web addresses you've previously visited), and buttons to help you move backward or forward in this list. Most allow you to save and/or print information and store web addresses in a list of "bookmarks" so you can return to the site in the future without having to remember and retype the address. 9.9.1. URLsA web page is what is displayed in a browser window when you type in a particular web address. This addresses is called a URL, Uniform Resource Locator. For example, the URL for the Prentice Hall web site is:
The components of a URL are the protocol to use to obtain the web page, the Internet address or hostname of the computer where the web page resides, an optional port number, and an optional filename. In the case of the URL above, the port number and filename were omitted, so the browser assumed port 80 and requested the default HTML file at the root of the web server document tree. The most common protocol is http (HyperText Transfer Protocol), which is the protocol for accessing HTML information. An encrypted channel, Secure HTTP, specified with https, is used for pages or transactions involving confidential information (e.g., credit card numbers). Most web browsers also support the ftp protocol, which gives you a GUI-based way of accessing anonymous ftp sites through your browser. If no protocol is specified, most browsers will assume "http://" goes on the front of the URL, so you can usually leave that off when manually typing in a URL. When you load a particular web page into your browser, you are typically presented with a nicely formatted display containing information and other highlighted text or icons (hyperlinks) that you can click on to be taken to other related web pages, possibly part of the current web site, or possibly managed by a completely different organization. The hyperlink is the fundamental concept at the heart of the World Wide Web. It results in a web of information, each page containing a link to many other pages. Since many web pages containing related information have links to each other, the result is a "web" of links all over the Internet. 9.9.2. Web SearchesSo now that you have a browser window and can access web sites, how do you find the information you want? I could list thousands of web sites that contain interesting information, but by the time this book is published, many of them might not be available anymore. Rather than just giving you a fish, I'd rather show you how to fish so you can find anything you might need on your own. There are more than a few web search engines on the Internet. These are sites that build and continuously update their database of web pages and keyword indices relating to them. Normally these are free services; the pages that show search results usually have advertising on them that sponsors pay for to support the cost of running the site. Some common search engines, in alphabetical order, include:
I have my own preferences and so will you. Your favorite may depend on the speed of the response, the layout of the information, the quality of the findings, the ease with which you can build a query, or some of the other services the site may provide. Today, there are so many sites on the Internet, the biggest problem with using a search engine is building a specific enough query so that you don't get thousands of links, most of which aren't what you really want. If you are trying to find a "regular company," you can often get lucky by guessing. A URL like:
probably works more often than not. 9.9.3. Finding Users and DomainsThe NIC provides web page access to the database of registered Internet users and Internet domains. The user database is not every Internet user, it is only users who have registered with the NIC. This usually includes system and network administrators who manage domain information for a site. The NIC's web site is:
and their web page can point you to the resources where you can perform all sorts of searches for domain and Internet information. |
EAN: 2147483647
Pages: 339