title: What do we actually import from Express in a Node.js program
body: <p>Usually when we import something in Node, we do something like:</p>
  
  <pre><code>const fs = require("fs");
  ... //use fs's methods for file system stuff
  </code></pre>
  
  <p>However, when we use express, we are doing:</p>
  
  <pre><code>const express = require("express");
  const app = express();
  app.get( .... )
  </code></pre>
  
  <p>What's the difference with the imports? why do we call <code>express()</code> like a function (I'm assuming it imports some function, and if it does, what does the function do)? In case it won't be explained by my previous questions, why don't we call function of the <code>express</code> object we imported?</p>