Graded pokemon cards mean that your card has been sent to a company that professionally grades your card. This means that the company certifies your card is genuine and rates it on a scale of one to ten based on how well printed it is and what condition it's in, among other factors. Once graded, the card is sealed in a transparent box or slab, with a sticker at the top dictating what Grade it is. Grades can range from 1 to 10, with grade 10 cards being both the rarest and the most valuable. Grade 10 pokemon cards can be sold for close to hundreds of dollars depending on the rarity and demand. There are four trusted grading services as of 2022: Professional Sports Authenticator (PSA), Beckett, CGC, and Ace Grading. PSA and CGC are most commonly used.