Glossary of Internet Terms

ASCII: ASCII stands for the American Standard Code for Information Interchange. This is a 7-bit code capable of representing 128 characters. Of these, 95 are "printable," 5 indicate "carriage control" (back-space, tab, line-feed, form-feed, and carriage-return), and the other 28 are used in communication control. A "plain text" file contains only printable and carriage-control characters, nominally with carriage-return and line-feed at the end of each line. Such files are easy to transfer between computers, and are guaranteed to be interpreted consistently.
binary: Any file that is not organized into printable lines or that contains 8-bit codes in the range 129-255, is said to be "binary." Examples include application programs, word-processor documents, and bit-mapped images. Special procedures may be needed to transfer binary files between computers.
browser: A World-Wide-Web browser is a client hypertext reader application program used to retrieve and view documents and images. Examples include Mosaic, NetScape, and Lynx. Browsers are able to interpret URLs and HTML formatted documents, and understand several Internet client-server protocols, such as HTTP, FTP, and Gopher. A browser may spawn or launch a helper or viewer application to display images or perform functions of which it is not capable.
browsing: Hypertext browsing means viewing and navigating through documents by scrolling the screen display or activating hypertext links to display additional documents.
CERN: Centre Europeen pour la Recherche Nuclaire (CERN) is a large particle-physics laboratory located in Geneva on the French-Swiss border. The World Wide Web originated at CERN.
client: A client is a application program running on your computer that contacts server system-programs on remote computers.
domain name: Computers on the Internet have both a "name" and a "number." Usually, a human uses the name and the computer looks-up and uses the number. A domain name consists of three logical parts separated by periods: computer-name "." organization-name "." organization-type-or-country. To make life easier for humans, most organizations have a specific computer named "www" as the primary World-Wide-Web entry point: for example, www.sri.com or www.nsf.gov.
FTP: The File Transfer Protocol (FTP) provides a scheme for transfering plain-text or binary files between computers. Many data-resource computers provide limited read-only access with the user name "anonymous" which is how WWW browsers fetch files from URLs of the form ftp://computer/file.
GIF: Windows-oriented WWW browsers (e.g. Mosaic and NetScape) can display images encoded in the Graphics Interchange Format (GIF), which is very popular, but has lower resolution and color diversity than the more general JPEG and TIFF image formats.
Gopher: Gopher is a protocol developed by the University of Minnesota for searching information data bases.
helper: A browser may spawn or launch a helper or viewer application to display images or perform functions of which it is not capable.
home page: The home page is an introductory document for a World Wide Web site, usually providing a general description of the organization and hypertext links to local resources.
HTML: The HyperText Markup Language (HTML) specifies rules for formatting WWW documents, giving hints to browsers about how they should be displayed, and encoding hypertext links (i.e. URLs) to other documents.
HTTP: The HyperText Transfer Protocol (HTTP) provides the language that the WWW browser uses to communicate with WWW servers. The basic activities are fetching files the user has requested and returning to the server information that the user has provided.
hypertext: A hypertext document is any document that contains links or pointers to other documents. No specific hierarchy or organization is implied. The collection of multiplly interconnected documents is called a "web" (rather than a "linear list," "tree," or "data base") from which comes the name World Wide Web.
Internet: In the beginning there was only ARPANet. Now there are thousands of local area networks that are interconnected to each other through gateways. The grand collection is called the Internet.
JPEG: From Joint Photographic Engineers Group, JPEG is a high-quality image format.
Lynx: Lynx (rhymes with "links") is a popular character-mode text-only WWW browser developed at the University of Kansas.
Mosaic: Mosaic is a user-friendly graphical WWW browser developed at NCSA (an accomplishment that, along with the NCSA HTTPD server, is the foundation of all the present popularity). NetScape is one of several commercial versions of Mosaic.
MPEG: MPEG stands for Motion Picture Experts Group and is an acronym for a common video file compression method.
NCSA: National Center for Supercomputing Applications (NCSA) at the University of Illinois, Urbana-Champaign, is a pioneer in making interconnected computers easier to use.
NetScape: NetScape is one of several commercial versions of Mosaic.
PPP: Point-to-Point Protocol software makes an Internet connection over a dial-up phone line (similar to SLIP).
protocol: A client-server protocol is an agreed-upon convention for the format and interpretation of messages exchanged between computers. Examples include FTP, Gopher, HTTP, NNTP(news), SMTP(mail), and TELNET.
searching: Hypertext searching means using text keywords that you enter to jump to a new location in the current document or to request that a remote data base server (e.g. Gopher) select additonal documents.
server: A server is a system program (also called a daemon) that is started when a client on another computer requests information. The server and client communicate using a client-server protocol. Each protocol normally has its own dedicated server.
SLIP: Serial-Line-Internet Protocol software makes an Internet connection over a dial-up phone line (similar to PPP).
TCP/IP: The Transmission Control Protocol/Internet Protocol (TCP/IP) is the basic specification of how data is exchanged between computers on the Internet. TCP/IP can be thought of as the language of the Internet. Technically speaking, TCP/IP provides error-free two-way communcation, like a telephone conversation, between client and server programs. Interpretation of the data exchanged is defined by the client-server protocol.
TIFF: The Tag Image File Format (TIFF) is a general graphic file format developed by Aldus Corporation.
URL: A Uniform Resource Locator (URL) is a scheme used to specify the location of a file somewhere on the World Wide Web. The syntax has the general form PROTOCOL://INTERNET.HOST/DIRECTORY_STRING/FILE_NAME.TYPE
viewer: A browser may spawn or launch a helper or viewer application to display images in formats that it does not understand, such as JPEG or TIFF.
WWW: The World Wide Web, also called the Web or W3.

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