title: Why wouldn't you want to use the `--save` option for npm install?
body: <p>I read about using the <code>--save</code> option <a href="https://stackoverflow.com/questions/19578796/what-is-the-save-option-for-npm-install">here</a> and and it says that it will add the installed package to your <code>package.json</code> file. But why isn't this automatic? Wouldn't you always want this? </p>
  
  <p>My understanding is that the <code>node_modules</code> is the directory that actually holds the code of your package and <code>package.json</code> is the reference/list of all the packages you have installed so that when you push it up to a repo, you only push the latter up and not the former, to save space. </p>
  
  <p>Then when other people clone or fork off your repo, they will have the <code>package.json</code> to reference and install all the necessary packages to work off of your project.</p>
  
  <p>Thus, wouldn't you always want your packages to be in the <code>package.json</code> in order for everyone to get what is needed?</p>