# Technical overview
# The core tech
In brief, the main technologies behind Apostrophe are:
- Express: Un-opinionated Node.js web framework. Express is the most widely used web framework for Node.js. Because it is simple, un-opinionated, and well-known, it was straightforward to extend it to suit Apostrophe's needs.
# Directory structure
There are a few directories and top-level files that are especially important in Apostrophe projects. Here is a rough overview of these files and folders you will see in the official boilerplate.
|Folder/File||What is it?|
| ||The heart of the application. This is where you tell Apostrophe what modules are in your project and set a few top-level parameters.|
| ||All project-level modules and configuration for installed modules.|
| ||Public, static files. Apostrophe will generate specific directories inside, but you can also use it as needed.|
| ||Template files that do not belong to any one module. Apostrophe looks for site wrapper templates here, including |
Core module configuration is all done in a subdirectory of
modules/@apostrophecms. This keeps core modules organized together and out of the way, following the npm scoping pattern.