title: Node modules size?
body: <p>I really can't understand what really happens when i run this command in my terminal <code>npm install</code>, after few seconds i find  node_modules folder with a size of at least 150MB or far bigger sometimes.</p>
  <p>This is too much for my network capacity, When i download a movie for example, this doesn't happen in that speed, so i need to understand what is really happening when i run this command.</p>
  <p>Do i really download a  150MB or more files size, or npm just download small files and do some work that makes it that big!</p>