title: Fundamental difference between Hashing and Encryption algorithms
body: <p>I see a lot of confusion between hashes and encryption algorithms and I would like to hear some more expert advice about:</p>
  
  <ol>
  <li><p>When to use hashes vs encryptions</p></li>
  <li><p>What makes a hash or encryption algorithm different (from a theoretical/mathematical level)
  i.e. what makes hashes irreversible (without aid of a rainbow tree) </p></li>
  </ol>
  
  <p>Here are some <em>similar</em> SO Questions that didn't go into as much detail as I was looking for:</p>
  
  <p><a href="https://stackoverflow.com/questions/184328/what-is-the-difference-between-obfuscation-hashing-and-encryption">What is the difference between Obfuscation, Hashing, and Encryption?</a><br>
  <a href="https://stackoverflow.com/questions/3080976/difference-between-encryption-and-hashing">Difference between encryption and hashing</a></p>