Core PHP Programming, Third Edition

26.1. Sprinkling PHP within an HTML Document

The first and most obvious approach to using PHP is to build HTML files as you have always done, inserting PHP tags as if they were HTML tags. This could take the form of repeating HTML that you replace with a call to a PHP function. It could take the form of a large block of PHP code that generates database output. Or it could be a script that processes a form submission. These are all situations in which the impact of PHP on the site is low. This is a good first step for those new to programming. You are able to insert the smallest amount of PHP code as a test. As your experience and confidence grow, so will your reliance on PHP.

Aside from simple tasks, such as inserting today's data with <?php ...