title: What does the ".align" directive mean in x86-64 Assembly?
body: <p>I notice that there's some directives used with the .align prefix followed by numerical values.</p>
  
  <p>I'm not sure on what this is, nor if it's even necessary to use, but I've wrote x86 Assembly and never used ".align" before.</p>
  
  <p>What is the basic purpose of it, and why or why not is it mandatory?</p>