HyperText Transfer Protocol
Although an understanding of HTTP is not strictly necessary for the
development of CGI applications, some appreciation of "what's under
the hood" will certainly help you to develop them with more fluency
and confidence. As with any field of endeavour, a grasp of the
fundamental underlying principles allows you to visualise the
structures and processes involved in the CGI transactions between
clients and servers - giving you a more
comprehensive mental model on which to base your programming.
Underlying the user interface represented by browsers, is the network
and the protocols that travel the wires to the servers or "engines"
that process requests, and return the various media. The protocol of
the web is known as HTTP, for
HyperText Transfer Protocol.
HTTP is the underlying mechanism on which CGI operates,
and it directly determines
what you can and cannot send or receive via CGI.
Tim Berners-Lee implemented the HTTP protocol in 1990-1 at CERN,
the European Center for High-Energy Physics in Geneva, Switzerland.
HTTP stands at the very core of the World Wide Web.
According to the
HTTP 1.0 specification,
The Hypertext Transfer Protocol (HTTP) is an application-level protocol
with the lightness and speed necessary for distributed, collaborative,
hypermedia information systems.
It is a generic, stateless,
object-oriented protocol which can be used for many tasks,
such as name servers and distributed object management systems,
through extension of its request methods (commands).
A feature of HTTP is the typing and negotiation of data representation,
allowing systems to be built independently of the data being
transferred.
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