Subscribers often receive a table of contents and they can then download specific articles. Usenet newsgroups are discussion groups related to specific topics. A network of host computers store and forward all sent messages for a few days then discard them. Anyone can connect to the newsgroup at any time, browse through the messages and leave messages, then disconnect. These are different from listservs in that you don't subscribe to them and nothing is sent to you automatcially, you connect when you wish.
Gopher is used to access information stored on computers around the world.
You select choices from menus until you reach your desired information. Telnet allows you to connect to another computer and operate it from your own keyboard. Computers can be closed to public access by requiring a proper account and a password for operation. These provide a list of available sources related to the search. You can find information you want by selecting relevant words in a document that lead you to another document.