What is PHP?
PHP (Hypertext Preprocessor) is a server-side scripting language used to create dynamic and interactive web pages.
Unlike HTML, which only displays static content, PHP can process data, interact with databases, and make websites work intelligently.
Key Features of PHP
-
Runs on a web server (Apache, Nginx, IIS).
-
Executes code before the page is sent to the browser.
-
Works smoothly with MySQL for database-driven applications.
-
Open-source and free to use.
-
Widely used in CMS like WordPress, Moodle, Facebook (early versions) etc.
Where Does PHP Run?
PHP runs on:
-
Server-side, not inside the browser.
-
Requires a local server environment like XAMPP/WAMP or a real web hosting server.
When you type localhost/myfile.php, the server interprets the PHP code and sends the output to the browser.
Common Uses of PHP
✔ Create dynamic web pages
✔ Handle HTML forms (login, registration, contact forms)
✔ Build database-driven websites
✔ Manage sessions and cookies
✔ Develop e-commerce systems
✔ Create API backends
Comparing PHP with JavaScript
You already know JavaScript from earlier classes. Here’s a clear comparison:
| Feature | PHP | JavaScript |
|---|
| Runs on | Server | Browser (client) |
| Use | Backend logic, database | Validation, interactivity |
| File extension | .php | .js |
| Who sees the code? | Hidden (server only) | Visible to users |
Simple Example
When run on a server, it outputs: Hello from PHP!
