The following screenshot shows you my Moodle application directory. Without even knowing much about Moodle, you can guess the function of several of the directories.
For example, the admin directory holds the PHP code that creates the administrative pages, the lang directory holds translations of the Moodle interface, and the mod directory holds the various modules.
The index.php file is the Moodle home page. If a student was browsing my Moodle site, the first page that the student would read is the http://moodle.williamrice.com/index.php file.
As each of Moodle's core components and modules are in its own subdirectory, the software can be easily updated by replacing the old files with new ones. You should ...