title: Differences between key, superkey, minimal superkey, candidate key and primary key
body: <p>I'm new to MySQL, and I'm really confused about the different terms that I've encountered. I tried googling the answer but the results are really confusing and when I try and understand it just seems like they are the same thing. </p>
  
  <p>What exactly are the differences among key, superkey, minimal superkey, candidate key and primary key?</p>