/LICENSES - Contains various licenses related to the application
/css - Contains a css styles file that can be applied to the application in the future
/js - Contains the main script.js file and eventListener.js
/lib - Contains various files related to Nextcloud, importantly /Controller, which contains all of the back end controllers that communicate with Nextcloud, like PageController.php
/templates - Contains the main.php file which defines the front end UI
/img, /src, /tests - All directories related to Nextcloud apps. 

Note: All of the instructions for installation and setup are explained in the readme.md, which can be viewed in our GitHub repo here: https://github.com/Akobke/usersync/tree/main

Further, the directories and file structure is all specific to NextCloud, not defined by us. 