Server-side scripting

Languages used in server side scripting.

Server-side scripting is a technique used in

client-side scripting where embedded scripts, such as JavaScript, are run client-side in a web browser

, but both techniques are often used together.

Server-side scripting is often used to provide a customized interface for the user. These scripts may assemble client characteristics for use in customizing the response based on those characteristics, the user's requirements, access rights, etc. Server-side scripting also enables the website owner to hide the source code that generates the interface, whereas, with client-side scripting, the user has access to all the code received by the client. A downside to the use of server-side scripting is that the client needs to make further requests over the network to the server in order to show new information to the user via the web browser. These requests can slow down the experience for the user, place more load on the server, and prevent the use of the application when the user is disconnected from the server.

When the server serves data in a commonly used manner, for example, according to the

protocols

, users may have their choice of a number of client programs (most modern web browsers can request and receive data using both of those protocols). In the case of more specialized applications, programmers may write their own server, client, and communications protocol, that can only be used with one another.

Programs that run on a user's local computer without ever sending or receiving data over a network are not considered clients, and so the operations of such programs would not be considered client-side operations.

History

Netscape introduced an implementation of

Netscape Enterprise Server, first released in December, 1994 (soon after releasing JavaScript for browsers).^[1]^[2]

Server-side scripting was later used in early 1995 by Fred Dufresne while developing the first website for Boston, MA television station WCVB. The technology is described in US patent 5835712. The patent was issued in 1998 and is now owned by Open Invention Network (OIN). In 2010 OIN named Fred DuFresne a "Distinguished Inventor" for his work on server-side scripting.

Explanation

In the earlier days of the web, server-side scripting was almost exclusively performed by using a combination of

mod_php) to the webserver. For example, WebDNA

includes its own embedded database system. Either form of scripting (i.e., CGI or direct execution) can be used to build up complex multi-page sites, but direct execution usually results in less overhead because of the lower number of calls to external interpreters.

Dynamic websites sometimes use custom web application servers, such as Glassfish, Plack and Python's "Base HTTP Server" library, although some may not consider this to be server-side scripting. When using dynamic web-based scripting techniques, developers must have a keen understanding of the logical, temporal, and physical separation between the client and the server. For a user's action to trigger the execution of server-side code, for example, a developer working with classic ASP must explicitly cause the user's browser to make a request back to the webserver.

Server-side scripts are completely processed by the servers instead of clients. When clients request a page containing server-side scripts, the application server processes the scripts and returns an HTML page to the client.