key flexfield is a field made up of segments, where each segment has both a value and a meaning. You can think of a key flexfield as an “intelligent” field that your business can use to store information represented as “codes.”
Most organizations use ”codes” made up of meaningful segments to identify general ledger accounts, part numbers, and other business entities. Each segment of the code can represent a characteristic of the entity. For example, consider an account number for a bank. A complete bank number may consists of various segments like the country code, area code, city code, branch code, account type, account number etc