Every CS2 skin has a float value between 0 and 1 that maps to one of five wear tiers: Factory New, Minimal Wear, Field-Tested, Well-Worn and Battle-Scarred.
Lower float generally means a cleaner finish and a higher price, but the jump in price between tiers varies wildly by skin — some look almost identical across wears, others change dramatically.
When comparing prices, always compare the same wear: a Field-Tested listing is not a like-for-like substitute for a Factory New one. Use the wear tabs on each item page to line up equivalent offers.