This is something that should’ve been covered in the 2nd tutorial. We’ll be discussing what the WordPress coding standard is.
I’m actually not going to write everything down, because everything is already written and explained on WordPress’s Codex. All information is clear and easy to understand. http://codex.wordpress.org/WordPress_Coding_Standards
If you don’t feel like reading, watch the video to get a good understand of what the WordPress coding standard is.