title: Firebase Cloud Functions: Difference between onRequest and onCall
body: <p>Going through the docs, I encountered:</p>
  
  <blockquote>
    <p>...you can call functions directly with an HTTP request or a <a href="https://firebase.google.com/docs/functions/callable" rel="noreferrer">call from the client</a>.</p>
    
    <p>~ <a href="https://firebase.google.com/docs/functions/#lifecycle_of_a_background_function" rel="noreferrer">source</a></p>
  </blockquote>
  
  <p>there <em>(link in the quote)</em> is a mention about <code>functions.https.onCall</code>.</p>
  
  <p>But in the tutorial <a href="https://firebase.google.com/docs/functions/get-started" rel="noreferrer">here</a>, another function <code>functions.https.onRequest</code> is used, so which one should I use and why? What is the difference/similarity between them?</p>
  
  <p>Documentation for <code>functions.https</code> is <a href="https://firebase.google.com/docs/reference/functions/functions.https#.onCall" rel="noreferrer">here</a>.</p>