Welcome! WordPress themes are one of the first and most important topics that one must understand to be good at WordPress development. Themes underlie the entire visual half of WordPress site, but often grow to do even more. We’re hoping your find these free content very helpful, as we think it covers some of the most important concepts in doing WordPress theme development for yourself.

“WordPress is a factory” is a core analogy designed to clarify what WordPress is as a technical system.

I really love being able to set custom image sizes in WordPress. The power and flexibility this system opens up for building beautiful, easy-to-administer, performant websites is hard to overstate.

One of the hardest things about teaching is the things that you’re blind to. There are whole things that you know, that are important for others to know, that you just kind of forget to ever explicitly teach.

I enjoyed reading Tom’s post about what file structure he uses in his themes for PHP functionality. I’ve never really made a WordPress theme with enough custom-function-based functionality to need much beyond five or ten custom functions in functions.php, but for a more complex case I think Tom’s strategy makes good sense. It’s definitely a place to start.