... Internet Basics ...
As he teaches, so he learns.

As a Web-user, you download files left and right. But do you really know what you are getting? Here's a list of file types, so you'll be able to pick and choose what you're getting just by looking at the extension:

* Extension .pdf: Acrobat file -- document with layout preserved.

* Extension .dll: Provides functions or data to a Windows program.

* Extension .doc: Document, like a Word document.

* Extension .xls: Excel spreadsheet.

* Extension .exe: Application program.

* Extension .jpg: Commonly used graphics program.

* Extension .dcr: Shockwave file -- enhances webpages with multimedia, such as animation.

* Extension .wav: Digitally recorded sounds.

Be forewarned about tinkering with DLL or EXE files unless you know what you're doing and you trust the source you're downloading from -- they could damage your system.

Chatrooms (and this is a personal point of view), are for the most part a complete waste of time. I've been there, seen it, done it, and most are nonsense. Of course, it depends upon the room; I've seen some on a very high caliber but… Anyway, if you want to see for yourself and you are a newbie, they can be overwhelming. Here are few tips for getting started:

• When you enter a chat group, a conversation is usually already in progress. You cannot see what went on before you entered.

• Wait a minute or two for a page full of exchanges to appear onscreen so that you can understand some of their context before you start reading, and then determine with whom you want to converse and whom you want to ignore.

• Start by following the comments from a single screen name. Then follow the people who that person mentions or who reply to that person. Ignore everything else because the other messages are probably replies to messages that went by before you came in.

After you can follow one thread, try picking up another. This takes practice to get the hang or it. Be patient -- with chat and with yourself. Word of warning: Be careful what personal information you give out; it's hard enough to know who people are in real time.

In addition to the well known e-mail, you can use chat rooms and newsgroups to connect with people around the world. In a chat room you conduct a real-time typed conversation with one or more people, and in newsgroups (sometimes aptly called bulletin boards) you read messages that have been posted, or post your own. You can even make Internet phone calls using your computer.

When you download something, you are copying it from a computer somewhere out there on the internet to your computer. You actually download things on a regular basis without realizing it. When you check your e-mail, your computer downloads the mail messages from the computer that acts as your mail server. When you view a web page, you are actually downloading the page from the computer that is hosting the web page to your computer. They go in your cache folder so you can view the page on your screen.

Uploading is simply the opposite of downloading. When I work on my web pages, I work on them on my computer until I am happy with the change, then I must upload the page to my server before they can be viewed by others. If I put a file up for others to download, I must first upload that file to a server.

Each webpage has a specific address, sometimes known as a URL (uniform resource locator). You can type the address to go directly to the page. It indicates a number of things: for example, http://geocities.datacellar.net/buddychai/ tells your browser to connect to my Web site (that's Buddy, yours truly), HTTP (Hypertext Transfer Protocol), tells your computer how to communicate with the world wide web, www. (Hypertext is a method of writing content for the Internet.) WWW indicates that the site is on the World Wide Web. The .com suffix indicates a commercial site (as .edu is used for educational institutions, or .org for other organizations).

The commonest way to move around the web is by clicking text or pictures called links, or hyperlinks, which have addresses coded into them. Your mouse pointer changes to a hand shape when it passes over a link. You can either browse (surf) the web at random or search for a page of interest to you by using a search service, which can search the Internet for words you specify.

Be extremely careful about putting identifying information about your children on your Web page. Just knowing your hobbies and your kids' names and where they go to school might be enough for some no-good-nik to pose as a friend of the family and pick them up after school.

Apply a simple formula like "your initials, plus the number 7, plus the first four letters of the URL. For instance (assuming you are John Smith), a Playboy password would be "js7play", and a Microsoft site would come up with "js7micr". You never have to check for passwords, and you always have them on the first shot, even for sites where you might have forgotten you've ever been. And what are you doing in Playboy?

The answer to a question about password complexity depends on the possible characters that comprise the password, and how many characters the password contains. If you only use the 26 characters of the English alphabet and your password is only 2 characters long, then you have only 676 (26 to the power of 2) possible passwords. A password-cracking computer program can guess any password of this length that you create from two letters in a fraction of a second.

If you choose your password from both lowercase and uppercase characters, numbers, the ten number keys, and the 32 special characters on your keyboard, such as the comma and the asterisk, then the number of distinct passwords increases to 9,216 (96 to the power of 2), which is still a low number.

However, if you make sure that the password consists of at least 7 characters, then the number of possible combinations increases to over 75 trillion, or to be exact -- 75,144,747,810,816 (96 to the power of 7). It would take a hacker over 2,300 years to try every possible combination if the password-cracking program tried 1,000 possible passwords every second.

Using a very powerful computer that tried one million passwords every second, it would still take 2.3 years. If you change your password every month or two, the password will most likely be different by the time the hacker has cracked it.

Getting a Server Not Found error is a common occurrence and often means that you can't get through. Usually, the Web server you're trying to reach is down, either temporarily or permanently. But often this message just indicates a glitch in the Net that keeps you from getting through, so try twice before you give up. Many surfers have gotten through to the Web sites they wanted to view by just trying again after getting an error message. So don't give up.

You may find pictures, sounds, or programs to download (install) to your computer from the Internet. Security settings help you download safely, to avoid unreliable software or viruses, and to make online shopping or e-mail communication more secure. Also, because some information on the web may not be suitable for everyone, there are programs built into browser where you can control what sites are viewable from your computer.