A dynamic web page is one that includes content that, rather than being hard-wired into the page, is generated on-the-fly from the web server. This means the page content can change based on a request by the user, by data being added to or modified on the server, or in response to some event, such as the clicking of a button or link.
Here's a general look at the steps involved in that process:
The PHP script receives the request and passes it along to MySQL.
MySQL uses the SQL command to extract the required information from the database and then return that data to the PHP script.