OKB is the name and trading ticker of the OKX crypto exchange's utility token. As is often the case with exchange tokens, OKB exists to reward consistent users of OKX by providing trading fee discounts, access to exclusive features, and more. OKB is also the native cryptocurrency of the OKExChain, hence its name (the "B" stands for "blockchain"). It houses products like OKX Earn and OKX Jumpstart, in which OKB has use cases as a utility token.
To make sure the value of OKB grows consistently, OKX employs a buyback program, as well as has designed it to have a limited supply. To avoid supply shock and make sure enough exchange users get to use it, its total supply is 1 billion OKB. The buyback-and-burn happens every three months, and the amount of OKB burned depends on the trading volumes of OKX.