Mosaic provides a hypertext interface to the Internet. Hypertext is text which contains highlighted links, called hyperlinks or anchors, to other texts. Each highlighted phrase (in color or underlined) is a hyperlink to another document or information resource somewhere on the Net. A single click with the left mouse button on any highlighted phrase will follow the link. To follow a link, in this sense, means that Mosaic will retrieve the document associated with the selected hyperlink and display it.
Hypertext can be plain text, images, audio, or video. Mosaic allows the display of text with inlined images, and also features unlimited multimedia capabilities. File types that Mosaic cannot handle internally, such as mpeg movies, sound files, Postscript documents, and JPEG images, are automatically sent to external viewers (or players) for display.
The Mosaic client communicates with HTTP servers. HTTP is the HyperText Transfer Protocol of the World Wide Web (WWW), which allows access to hypertext information across the network. Mosaic can also communicate with more traditional Internet protocols such as FTP, Gopher, WAIS, NNTP, etc. Since Mosaic was introduced only a few months ago, the number of WWW servers and the WWW traffic over the Internet has increased dramatically. Requests for the NCSA WWW server have been increasing at 11% per week. Sun Microsystems set up a Mosaic/WWW server for information on the Winter Olympics that was handling up to 100,000 users per day and 32,000 page requests per hour.
All NPAC InfoVision applications and demonstrations, including video on-demand, simulation on-demand, image and text on-demand, and access to educational information, have been or can be made available across the network under Mosaic.