Concerning the folders you mentioned: /libs is usually used for custom classes/functions/modules /vendor or /support contains 3rd party libraries (added as git sub-module when using git as source control) /spec contains specifications for BDD tests. /tests contains the unit-tests for an application (using a testing framework, see here) NOTE: both /vendor and /support are deprecated since NPM intro
![Folder structure for a Node.js project](https://cdn-ak-scissors.b.st-hatena.com/image/square/98d6f053a97a87156775f60757c60865d0f2c47d/height=288;version=1;width=512/https%3A%2F%2Fcdn.sstatic.net%2FSites%2Fstackoverflow%2FImg%2Fapple-touch-icon%402.png%3Fv%3D73d79a89bded)