As you use the Internet, you notice people talking about joining "lists" and participating in discussions on various subjects. While there are thousands of ongoing newsgroup discussions about different subjects, there are also thousands of e-mail list discussions happening as well.

What's the difference? Newsgroups are public discussions that anyone with a news reader can subscribe to and participate in. You read what others have written and post your own reply. A mailing list, on the other hand, is simply a list of e-mail addresses of people interested in the same subject. Someone sends out a message and it goes to everybody on the list. You can reply to the messages, send new messages, or just lurk, reading the messages without participating. It's up to you.

Each time you or anyone else on the list posts a reply, it's distributed to the e-mail box of everyone else on the list. All of this traffic is automatically managed by programs called Mailing List Managers (MLM'S) or Mail Servers. The two most frequently used MLMs are Listserv and Majordomo. The key advantage of a mailing list over a newsgroup is that instead of having to go somewhere to read or retrieve the contents of a discussion, it is automatically sent to you via e-mail.

How does it work? To subscribe, you send an e-mail message to the list administrator and your e-mail address is added to the list. You'll receive a reply that gives you all the details you need to know about the list and how to participate. Soon, you'll begin receiving mail from other list members.

Mailing lists can be public or private and involve as few as two people or as many as thousands. There are generally two types of lists:

• With announcement-type lists, you receive messages, but don't post to the list yourself.
• With discussion-type lists, everyone on the list can join the "conversation."

Unlike Usenet newsgroups, which require additional software to run, all you need to participate in a Mailing List is an e-mail address. Subscribing to a mailing list doesn't mean you have to pay money; it just means you are asking to have your e-mail address added to the distribution list. To get off the mailing list, you have to "unsubscribe" from it. This process is handled by sending a particular type of e-mail message to the list administrator with your request. In the body of the message you type something like unsubscribe followed by the name of the list and your e-mail address. The process varies from one list to another, depending on what Mailing List Manager the system uses.