The official Codex page lists some important files, but only for WP version 2.x and doesn’t seem to list files located in all sub-directories. Surely it’s not very exciting topic in the world, but it’s always good practice to know the files structure. By this, You can get to see the bigger picture and gain a better understanding of how much stuff actually is included in WordPress — especially when you like to start digging around in the /wp-includes/ directory.. bring a snack, knife, and some flint to improve your chances.
We’re going to download and unzip of WordPress version 3.4.1 — a complete list of all files in all directories. Here’s the steps: