Understanding PHP theoretically, is only the beginning of actually truly knowing it. Once you sit down and start writing code, things will seem to magically clear up as you go along.

He gives examples of web application types and talks a bit about databases, a "key part of most web applications".

• Part 1 - This is a hands-on video where I hope the viewer will actually write code along with me. I want to stress that this video (like everything else on this site,) targets beginners .. not old PHP hacks.
• Part 2 - In this video, we actually use the object we created in Part 1, in our PHP page.
• Part 3 - In this video, I clarify a point I was trying to make in part 2. In a nutshell, I talk about why it makes sense to keep any page rendering code (HTML and CSS) out of your business logic classes.

Lots of other videos (on different topics too) are also posted on Stefan's website.