CGI - Common Gateway Interface
CGI is the interface between a server (A WWW server is a program that web browsers such as Mosaic and Netscape can obtain hypertext from. It must run on a computer attached to the Internet) and the other resources of the server's host computer.
Client Process :
The client is a process (program) that sends a message to a server
process (program), requesting that the server perform a task (service).
Client programs usually manage the user-interface portion of the
application, validate data entered by the user, dispatch requests to
server programs, and sometimes execute business logic. The client-based
process is the front- end of the application that the user sees and
interacts with. The client process contains solution-specific logic and
provides the interface between the user and the rest of the application
system. The client process also manages the local resources that the
user interacts with such as the monitor, keyboard, workstation CPU and
peripherals. One of the key elements of a client workstation is the
graphical user interface (GUI). Normally a part of operating system
i.e. the window manager detects user actions, manages the windows on the
display and displays the data in the windows.
Server Process
A server process (program) fulfills the client request by performing the
task requested. Server programs generally receive requests from client
programs, execute database retrieval and updates, manage data integrity
and dispatch responses to client requests. Sometimes server programs
execute common or complex business logic. The server-based process
"may" run on another machine on the network. This server could be the
host operating system or network file server; the server is then provided
both file system services and application services. Or in some cases,
another desktop machine provides the application services. The server
process acts as a software engine that manages shared resources such as
databases, printers, communication links, or high powered-processors. The
server process performs the back-end tasks that are common to similar
applications.
Some of these programs understand the Hypertext Transfer Protocol, and they receive requests for information in a given
Uniform Resource Locator, find that information on their local disk drives and then return it to the browser.
Other programs called "gateway" programs convert a different information format to hypertext and then return it to the browser.
Other non-HTTP servers such as FTP or gopher servers can also be accessed by WWW browsers.
In order to make your information available via World Wide Web, you must either start your own server or "piggyback" your
documents on an existing server.
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