Lektor themes work like an extension of the project, allowing you to easily adopt features of the theme such as styles, models, or templates. In all, themes can provide:
* templates
* models
* flowblocks
* assets
Themes can provide all of these as defaults which can be overridden or extended by your project. For instance, if a theme provides a root `page.html` template, you can create other templates that `{% extends "page.html" %}`, or you could override the theme's `page.html` by providing your own in your project's normal `templates/` directory.