title: Not understanding auto layout, constraints and size classes
body: <p>I'm a bit stuck and any help would be greatly appreciated!</p>
  
  <p>I'll give you a quick overview. I have designs for a screen that were built in sketch using an iphone 6 screen size, then redesigned to fit and look right for an iphone 5/5s/5c, and 6 plus as those are the only devices that I want to support.</p>
  
  <p>But the design portion or implementing the designs for just one specific screen size is easy and I understand that part. Where am I'm lost completely, is how to implement a design in one view controller that looks the way that it should in all the screen sizes I designed for.</p>
  
  <p>I've gone through more than a few auto layout and size class tutorials and not sure how I properly use them so that the app recognizes "this is an iphone 5, use these image sizing and placements instead, and this is an iphone 6 plus, use these" and so on.</p>
  
  <p>Everything I've seen to this point regarding auto layout and constraints only use 1 set of numbers to judge distance from elements for example, but all screen sizes would have different distances.</p>
  
  <p>What am I missing or not understanding? I know I'm looking at something improperly.</p>
  
  <p>Thanks in advance for all help!</p>