You read what other members have written and can post a reply if you choose. A mailing list, on the other hand, is a list of e-mail addresses of people interested in the same subject. When a list subscriber sends a message, it goes to everyone on the list. You can reply to the messages, send new messages, or just lurk, reading the messages without participating. The key advantage of a mailing list over a newsgroup is that instead of having to go somewhere to read or retrieve postings, messages are automatically delivered to your e-mail box.
Mailing lists can be public or private, and involve as few as two people or many thousands.
Mailing lists are often used to provide subscribers with current information. For music fans, that might include upcoming concert dates or ticket purchasing details. With announcement-type lists, you receive messages, but can't post to the list yourself. With discussion-type lists, everyone on the list can participate. To join a mailing list, all you need is an e-mail address.