Working Of Online Php Program And Relation Ship Of Client And Server

Saturday, 16 March 2013

Working Of Online Php Program And Relation Ship Of Client And Server

How Does Online Php Program Work?

Php Program And Relation Ship Of Client Server

Working Of Online Php Program And Relation Ship Of Client And Server

Now we are moving towards some practical implementations of php web development.Many of friends may have confusions in their minds that

How does a php program run and work?
What is the relationship between client and server?

So we will try to answer these questions in this post in depth.

Working Of Php :

Php is not like those desktop softwares that run on our local disks. We know that the extension of these softwares is .exe and they are executable. But php online program runs only when a request is sent to the server by the client and that request asks for running a particular file on the web server. The web server executes the file notified by the request and sends the output result of that file back to the client. But before the response of the web server, It is checked that the request file is whether a php file or not. If it is a php file then Php engine is given a chance to process the php script of that file. But the point here to be noted is that a web server can run only one file at a time. Therefore we can request only one file from server. Although we can add external files on our page by Include Or Require constructs. It means that we copying them in our page dynamically while original file is only one which is on web server. ( We will discuss and explain Include and require Constructs in our next tutorials ). A Http Request completes when a page is processed till end and after completion of HTTP Request, all the data and variables used in this processing will be removed.

What Is A Client And Server?

Client And Server

The Program Which Interacts With server is called Client. The program which provides services to client is called a Server.

For Example Browsers (Google Chrome, Firefox, and Internet Explorer), Email Clients/Senders and FTP are all " Client " programs and run on Client System. These Client programs are connected to servers and perform different function because of this connection to server.

Examples of The " Servers " to which Clients are connected are Web servers , FTP Servers , Email Servers etc

Relation Ship Between Client And Server :

Relation Ship Of Client And Server

Relationship of Client And Server is very important in Php because all the Php code runs and executes on server while HTML and JAVA SCRIPT code present on the server is returned as it to the client without processing. "JavaScript" is a language processed by a Web browser. Php code is processed on Server. Therefore the processed Php page is sent by server and you will not find the php code in the source of the processed page.