title: What is the meaning of the "at" (@) prefix on npm packages?
body: <p>In the <a href="https://docs.angularjs.org/guide/component-router" rel="noreferrer">Angular Component Router documentation</a> I just stumbled over a npm command I have never seen before and I don't understand what is going on:</p>
  
  <pre><code>npm install @angular/router --save
  </code></pre>
  
  <p>What is the meaning of <code>@angular/router</code>?</p>
  
  <p>Is the whole string a package name? But then I dont find that package when I use the search on <a href="https://www.npmjs.com/" rel="noreferrer">npmjs.com</a>.
  And also the commandline search does return no such package:</p>
  
  <pre><code>npm search @angular/router
  :No match found for "@angular/router"
  </code></pre>
  
  <p>So is the <code>@angular/</code> some kind of prefix mechanism in npm? And how does it work?</p>