title: How does the npm script in package.json 'know' where the files are (angular 2.x)?
body: <p>I'm developing in Windows 7 on Chrome using Angular 2.4 (not using Visual Studio) and downloaded the <a href="https://angular.io/docs/ts/latest/guide/setup.html" rel="nofollow noreferrer">quickstart</a> and all is working fine.</p>
  
  <p>Now, I want to see the version of 'node' I'm using, thus I type <code>node -v</code> at the command prompt in the project's folder (where the <code>package.json</code> file is) the and all is fine.</p>
  
  <p>Now, I want to see the version of Typescript I'm using, thus I type <code>tsc -v</code> but it cannot find it.</p>
  
  <p>If I put a script in <code>package.json</code> like <code>"tsc-version": "tsc -v"</code> and then I run <code>npm run tsc-version</code> command, I do get the Typescript version number.</p>
  
  <p>How does <code>npm</code> knows where the <code>tsc</code> javascript file is? </p>
  
  <p>I know it has something to do with the folder structure, and how does the  <code>./node_modules/.bin</code> folder come into play?</p>
  
  <p>Can anyone explain what is going on here? </p>