title: Dev dependencies vs dependencies in node.js
body: <p>In a node project I found 2 kind of dependencies:</p>
  
  <pre><code>    "dependencies": {
          "axios": "0.9.1",
          "express": "4.13.4",
          "lodash": "4.6.1",
          "react": "^0.14.7",
          "react-dom": "^0.14.7",
          "react-redux": "^4.4.0",
          "react-router": "^2.0.0",
          "redux": "^3.3.1"
        },
        "devDependencies": {
          "babel-core": "^6.5.2"
  }
  </code></pre>
  
  <p>I know the author install it via <code>npm install babel-core --save -dev</code></p>
  
  <p>but what is that for? when you push your code, the <code>devDependencies</code> module is still there.</p>