Documentation
Modularity compiles and loads modular components from your theme. It regards all modules inside your-theme/modules/ where all files are optional:
example/
example.php --------- included
example.template.php
example.scss -------- compiled, prefixed, enqueued in front-end
example.editor.scss - compiled, prefixed, enqueued in editor
example.block.scss -- compiled, prefixed
example.js ---------- enqueued in front-end
example.editor.js --- enqueued in editor
*.scss -------------- compiled, prefixed
languages/ ---------- loaded
submodules/ --------- modules inside are processed alike
readme.md
The style.css of your theme is enqueued in front-end and editor as well.