title: Why some MySQL data type require some extra bytes?
body: <p><img src="https://i.stack.imgur.com/7mBn0.png" alt="enter image description here"></p>
  
  <p>I was reading about the MySQL data type size. I saw VARCHAR takes extra 1/2 bytes, MEDIUMTEXT requires extra 3 bytes, LONGTEXT requires extra 4 bytes. What is the reason for such MySQL behaviour?</p>