title: How does Node.js do synchronous 'require()' calls so quickly during runtime?
body: <p>How does Node.js do synchronous 'require()' calls so quickly during runtime? With Java, we can build binary files before execution using a build tool like Maven. But with Node.js we don't really have build tools, yet the CommonJS synchronous require() statements embedded in our Node.js code surely must be some of the slowest lines of code in our Node.js programs but how do they run so quickly considering that they are loading files at runtime?</p>
  
  <p>Here is some info about CommonJS modules: 
  <a href="http://fredkschott.com/post/2014/06/require-and-the-module-system/" rel="noreferrer">http://fredkschott.com/post/2014/06/require-and-the-module-system/</a></p>