Explain the difference between PHP and HTML?

PHP and HTML are both languages used for web development, but they serve different purposes and have distinct characteristics:

1. Purpose:

   • HTML (Hypertext Markup Language) is a markup language used to create the structure and content of web pages. It defines the elements and layout of a webpage, such as headings, paragraphs, images, links, and more.
   • PHP (Hypertext Preprocessor) is a server-side scripting language used for creating dynamic web pages. It can generate HTML content dynamically based on various factors such as user input, database queries, or system variables.

2. Execution:

   • HTML is executed by the client's web browser. The browser interprets the HTML code received from the server and renders it into a visual webpage that users can interact with.
   • PHP, on the other hand, is executed on the web server. When a PHP file is requested by a client's browser, the server processes the PHP code, generates HTML content dynamically, and sends the resulting HTML to the client's browser for display.

3. Static vs. Dynamic Content:

   • HTML creates static web pages, meaning the content remains the same unless the HTML file is modified. Changes to the content require manual editing of the HTML code.
   • PHP allows for the creation of dynamic web pages, where the content can change based on various factors such as user input, database queries, or system variables. PHP code can generate HTML content dynamically, allowing for more interactive and personalized web experiences.

4. Features:

   • HTML provides basic structural elements and formatting for web pages, such as text, images, links, tables, forms, etc.
   • PHP provides more advanced features for web development, such as database integration, session management, form handling, file manipulation, authentication, and more. It enables developers to build complex web applications and websites with dynamic functionality.

5. File Extension:

   • HTML files typically have a .html or .htm file extension.
   • PHP files have a .php file extension, indicating that they contain PHP code that needs to be processed by the server before being sent to the client's browser.

In summary, while HTML is used for creating the structure and content of web pages, PHP is used for generating dynamic content and implementing server-side functionality, allowing for more interactive and feature-rich web applications.