Please make a note of this change. Today's Internet activity is much more than just E-mail and FTP file transfers. In the 1990s a number of new information retrieval tools have sprung up on the Internet, and their capabilities are being tapped by the world's astronomers. All three are client-server systems. This means that a software program running on the user's end, called the client, communicates with a different program at the information database site, known as the server, to transmit requests and pass back information.
Gopher is a system for searching hierarchical directories on servers anywhere on the Internet.
WAIS takes a different approach to information discovery. It allows users to submit a free text query that is compared to the entire contents of the text information files in one or more data bases. A ranked list of documents that relate to the user's query is returned to the user. The user can select one or more of these documents on the list to retrieve and browse. Images, animation, and sound can be accessed across the Internet in addition to text and data.