What is PHP? Definition and explanations
PHP is a server-side programming language originally designed to produce dynamic web pages. It runs a large share of the existing web, notably WordPress, Drupal and many e-commerce sites. Its 8.x releases brought significant performance gains and stricter typing, far from the permissive reputation it carried in the 2000s.
In one sentence
PHP is a server-side language that runs a large share of the existing web.