• text-based means for communicating over the Internet
• e-mail usually used to communicate with one person or a few people
• newsgroups provide a discussion forum
  • messages are viewed by hundreds or even thousands of people
  • e-mail can be used in this fashion, but
  • newsgroup software enables users to easily "follow the thread" of a discussion
• newsgroups are appealing to people who share common interests or health concerns.

The following two websites provide addresses and subscription instructions for tens of thousands of e-mail and newsgroup discussion lists:
E-mail discussion lists (ListServ): http://www.liszt.com/
Newsgroups (Usenet): http://www.liszt.com/news/