It is used by almost 40% of websites.
Where PHP is used
WordPress also uses PHP. In addition, it is used by Wikipedia, Facebook and Tumblr. Used on the server side. This means that the PHP code runs on the server where your WordPress site is hosted. PHP is used to generate the html code of the site, which the server sends to the browser.
You need to be careful and choose the right WordPress hosting , preferably with the support of the latest version of php.
Official site: php.net