It's stupid and the "common core" equivalent to tech. Just some crap people pretend they know what it means. You can come up with Flops several different ways because it's calculated with a formula.
You can have a blazing fast 12TFLOP or a slow pos 12TFLOP because it's calculated using number of cores x speed x floating points (don't bother researching this) divided by 1 trillion or billion. So if you have like 3000 cores with slow speeds, that can equal 1500 cores with faster speeds. It's a gimmick for idiots.
Go with pure specs. That's all that really matters.