 Mini-lecture on the World Wide Web |
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The World Wide Web is an Internet service which is based on a specific protocol (or communication
standard) which allows computers to share information. The Web standard is called HTTP,
which stands for Hypertext Transfer Protocol. Every computer that communicates over the
Web has to be able to share hypertext documents using this standard. So it makes no difference if
one person who is using an IBM-compatible computer wants to communicate with someone who
is using a Mac, and even if a computer with a UNIX operating system is facilitating their
exchange. As long as all three computers can encode their information in the appropriate
HTTP format, the communication can take place.
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Supplemental links
(not a required part of the course)
HTTP
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After the days of stand-alone systems, when networks of computers first started becoming able to
communicate using a standard protocol and the
Internet was born, the "Web" still didn’t exist. At this early stage of the
Internet, a person had to use separate command-line programs to access different types of
information. To log on to a remote computer and run programs, a person had to
"telnet." To send or retrieve a file from a remote computer, a person had to run
an FTP (file transfer protocol) program. To search for files on another computer a person
would run a Gopher program, and so on. |
HTTP related protocols |
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The programs were all text based. The commands had to be typed in. And all display was
in text only. So even if you were retrieving an image file from another computer, you
still needed an image viewer program on your own computer in order to view the image once
you had retrieved it. The files that were retrieved were simple text files
or binary files (such as programs or images). But they weren't hypertext
documents.
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