Glowing includes 5 other folders. Please see explanation below for more details:
assets: Store less, js, resource default and another plugin for theme. Besides include file for demo data.
g5plus: Store template that contains blog and core
inc:Store all functions and plugin of G5
languages: Store .pot file for translate to another language
templates: Store templates for header, footer, archive, comments, breadcrumb.
ube: Store templates for header, footer, archive, comments, breadcrumb.