PHP is a server-side scripting language initially created for Web development to generate dynamic Web pages.

You can embed PHP code into HTML code or use it with numerous web content management systems, frameworks, and templates. It is typically processed by a PHP interpreter, a web server, or a combination of the two. The result is a Web page that contains dynamic content generated by the PHP code.

PHP is still one of the most popular scripting languages for web development for many reasons: 

• It is easy to learn for beginners.

• It is open-source, which gives generous permissions allowing code reuse.

• It is free to use. 

• Many other high-level languages compile into it, e.g., Java and C#, making it possible for programmers with knowledge in those languages to create a website quickly.

• A large assembly of users who share their experience in the form of free tutorials and solutions to problems

• Flexibility is used for all types of web development: large, complex e-commerce applications and simple one-page websites (e.g., Wikipedia). 

• Many extensions, libraries, and APIs are available, allowing a programmer to select the best tools according to the type of task at hand.

• A large community of software engineers can get hired for projects.

PHP has been the language of choice for many companies that cannot afford to develop their infrastructure and rely heavily on open source solutions. In addition, many high-profile Web sites including Facebook, Wikipedia, WordPress, and Digg, are either built entirely on PHP or use it extensively.