Websites with designs that are based solely on the venerable HTML format are, by all appearances, static.
A viewer will access the page, read the content, and then leave.
Basically, a static webpage is one that lacks dynamic or interactive content.
For these exciting features to be possible, a website must employ programming technology that specifically allows them.
A major player in this field is the Common Gateway Interface, or CGI.
CGI enables users to interact with the website server in a more sophisticated manner.
Needless to say, the technology led to various possibilities and radically altered the way people use the internet for their purposes.
CGI works by providing the platform for users to access non-standard, web-based content.
Basically, an application that is operated from the web server enables this process as long as the content is in another server that allows it too.
The application mentioned is called the common gateway.
Using this gateway practically lets users interact with a website directly, in that it gives access to content that is usually not found in that site, or is impossible for the site to render per se.
The concept becomes even better as more technological advances are developed.
Currently, several websites employ CGI to run a variety of complex programs written using different programming languages.
Such applications can be highly-sophisticated games, online shopping portals, music libraries, and other similarly interesting programs.
Depending on the aplomb of the programmer, the uses of CGI in websites are almost limitless.
This technology is therefore extremely popular to people online.
However, it is to be noted that CGI files are in a nonstandard format than what is usually found on a server and since the common gateway application enables direct access to the server, it can degrade security somewhat.
Fortunately, this is remedied by having CGI run in its own directory.
The concept works by letting the server administrators handpick the elements that can be accessed through CGI.
That way, the remaining files stay safe from possible attacks or unauthorized users that might employ the common gateway as the access point.
The directory, usually called CGI-BIN, has another use as well.
Mainly, this other purpose also involves website security.
A CGI file that is excluded from the CGI-BIN folder will be rendered by a browser application the way it does other content, which is through standard web coding language.
However, this will not work for the CGI file since CGI is a program in itself, and so the user attempting to access it would not be able to see anything, with the server eventually generating something else for that user.
Conversely, files within the folder are treated by the server in a special way, because these are run by a different program unlike those that run regular web files.
Alternatives To CGI
Common gateway interface technology now shares the limelight with other similar coding concepts that are just as useful.
In fact, some of the newer ones like PHP and ASP work identically to CGI, but provide more security in file management and omit the use of subfolders.
Instead, these two are run from the same directories that include the usual HTML pages, being different only in that PHP and ASP pages are typically dependent on respective MySQL databases to run.
Therefore, the information is not found in a folder but rather in a separate server.
Another edge they have over CGI is that they are substantially faster and use lower bandwidths to run, and thus more efficient.
CGI wins over PHP and ASP only when it comes to the number of complicated applications it can run per server, and it is this edge that lets it keep its importance in the online programming field.