A Diamonds Clarity is measured by the existenc or absence of flaws. Ranging from Flawless, very slightly flawless, slightly flawless & included. Within these ranges you have a range of 1 or 2, with 1 having less inclusions than the 2 range. The chart represents these ranges, but a chart is nothing like looking at the real thing. Depending on the size & the clarity of your Diamond, you may see it with your naked eye or you may need 10X magnification.