Why does npm install install a bunch of libraries after defining package.son?

  node.js, question

Json

bracket
 "name": "my-project-name",
 "version": "0.1.0",
 "devDependencies": {
 "grunt": "~0.4.5",
 "grunt-contrib-jshint": "~0.10.0",
 "grunt-contrib-nodeunit": "~0.4.1",
 "grunt-contrib-uglify": "~0.5.0"
 bracket
 bracket

Json directorynpm installThere will still be a bunch of libraries installed, not just the ones defined above, Why?.

The newer version of npm will install all the dependencies in one directory instead of the tree structure.