Trying to understand how PHP and MySQL works - Am I understanding correctly?

[Astano]

1. A client connects to the server.
2. The server then processes the PHP which can connect to a database, MySQL for example. A database stores information in tables which are formed of rows and columns, imagine an Excel document.
3. Once the PHP has got the information from the database it will then output text.
4. If the text is in a format the browser understands, HTML for instance it will be rendered.

Websites like facebook use a database to store information about a person which is then accessed by PHP and rendered by a clients browser as HTML.