Introduction to the PHP Language for Beginners
The PHP language is designed for creating dynamic websites. With its help, for example, you can make a forum, an online store, a bulletin board, and similar things.
Technically, PHP is needed for generating HTML code. As a rule, the texts of your site are stored in a database. PHP interacts with the database via the SQL language, retrieves the texts, and forms the final HTML code from them, which is then sent to the user's browser.
To learn PHP, you need to know the basics of markup, at least at the level of the main markup book.