Mailing lists are essentially emails that are distributed to more than one person. When you join a list, you become a "subscriber" to that list. There are an estimated 200,000+ lists on the Internet. They cover as general subjects as "Small Business" to really specific things like "sushi-lovers." There is really something for everyone... and if you don't find one that suits your needs, you can always start your own! Mailing lists can either be one-way or two-way. Two-way lists include discussion lists. Discussion lists can be moderated or unmoderated. When you send an email to a discussion list, you are "posting" to the list. Moderated means a human screens each post before it gets distributed to the list. Unmoderated means posts are typically sent out immediately to other subscribers of the list. Some discussion lists are distributed in a post-by-post format. Some are distributed in only a digest format (i.e. a collection of multiple posts). Other lists offer both digest and post-by-post options. One-way lists include announcement lists, e-zines and newsletters. Generally, one or more person is responsible for editing the list.