Introduction to PHP
PHP is an open-source server-side programming language, also called the use scripting language, embedding the code of PHP into the code of API HTML. The full form of PHP is Hypertext Preprocessor, its original name is Personal Home Page. It was created by Ramsum Lerdorf in 1994.
Php runs on all platforms like Windows, Linux, Unix, Mac, OS, Etsy.
PHP file ka extension .php
What we can do with PHP?
-Can create dynamic pages with PHP.
-Handle button click, radio button:-
Through PHP you can handle the button click event
-Create database application
-online shopping cart
<!DOCTYPE html> <html> <body> <?php echo"Helllo World"; ?> </body> </html>
What are client and server?
A client is a piece of computer hardware or software that accesses a service made available by a server. For example, web browsers are clients that connect to the web servers and retrieve web pages for display.
A server is a computer program or a device that provides functionality for other programs or devices, called “client”.
There are many servers like: web server, mail server, print server etc.
Client server Architecture:-
2-Tier Architecture:- A 2 Tire Architecture is where the client talks directly to a server.
3-Tier Architecture:- Middleware
If the client has sent the request to the application server, the application server checks that the request is made by the client. If the request is in its data source, then that application server will respond to your request.
Web Browser and Web Server
The web browser is a client, program, software, or tool through which we sent HTTP requests to a web server. It knows how to communicate whit the server. The main purpose of a web browser is to locate the content on the World wide web and display the web page, images, audio, or video form.
A web server can be either a software unit or a hardware unit, which provides the web pages via HTTP. The web server gets the request and finds the resources than the response to the client. The web server provides service only for web applications. All the communication between client (web browser) and server takes place via HTTP.
Web server architecture
A web application or web app is a client-server software application in which the client runs in a web browser.
What is a Website?
Website is a collection of related web pages that may contain text, images, audio, and video. A website can consist of one page, depending on what the site owner is trying to accomplish.