It is about time. What is a Tad, Dash, Pinch or Smidgen?

While I was out walking around the massive amounts of people trying to get those sometimes good black friday deals I found these… I needed a new set of measuring spoons and the ones I got came with this extra set. I just wonder what the actually equate to? So if you really need a “tad” of thisĀ  or a “dash” of that, or a “pinch” here or a “smidgen” there, these are supposed to be what those “terms” equate too…