Client side scripting
At present there are a number of client side technologies, such as JavaScript, CSS, flash movies, Java applets, and others that improve the interactivity of the webpage for the client. These technologies primarily improve the three area of presentation, navigation, and validation. All of these technologies send additional informal with the webpage, which is processed by the client computer, and does not rely on the server.
In other words, without these technologies every interaction with the user would need to be sent to the server. The server would need to determine the response and that response would then have to be sent to the client. This is a long and timely process. Users would get frustrated with and the server is doing a lot of work. A more powerful server means a more expensive server. Therefore it is better for the client and server that these tasks are done at the client side.
Client side technologies enable the web designer to add interactivity to there web page, but what happens when the page needs totally different data, i.e. the products have changed, or a different type of user (Manager not a shopper). In both of these case the web developer would not would to sent the same static web page, but link it to a database or dynamically chose a second version of that page. This can only be done by server scripts.
Server side Scripting
In other words, without these technologies every interaction with the user would need to be sent to the server. The server would need to determine the response and that response would then have to be sent to the client. This is a long and timely process. Users would get frustrated with and the server is doing a lot of work. A more powerful server means a more expensive server. Therefore it is better for the client and server that these tasks are done at the client side.
Client side technologies enable the web designer to add interactivity to there web page, but what happens when the page needs totally different data, i.e. the products have changed, or a different type of user (Manager not a shopper). In both of these case the web developer would not would to sent the same static web page, but link it to a database or dynamically chose a second version of that page. This can only be done by server scripts.
Server side Scripting
Is the ability of the server to process the requested page before it is sent to the client. This means that the sever can decide when parts of the webpage are sent. It can retrieve data from a database and build this into the webpage. It can detect which browser is being used by the client and customise its webpage appropriately. All these thing and more can be done using a variety of programming languages/scripts.
Common Gateway Interface
Common Gateway Interface
With the demand for WebPages to be connected to databases, files and directories, there was a lot of development in the area. What resulted was a standard how a web server could request these activity from a script/language. Thus the common gateway interface (CGI) was born. CGI is a set of standards that defines how a web server can interface with an application program. This interface allows data to be transferred between both parties.
Application Program
Application Program
This is a program sitting on a server that has been written to do a specific job, like check login credentials (username & password). This checking could be hard codes, held in a file, or read from a database. It dose not matter.
These programs can be written in a number of languages C/C++, Java or scripts such as ASP, Perl, PHP, and Clod Fusion Markup Language.
We will consider some of the script languages in further posts.
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