A universally unique identifier (UUID) is a special code made up of numbers and letters that helps identify something. It's like a super-special serial number that is used to easily identify computers, applications, websites, and more. Think of it like a fingerprint that we can assign to different items - no two UUIDs are ever the same. They are also really long: a UUID is usually made up of 32 characters, though some UUIDs can be even longer. We use UUIDs to make sure that things can be easily tracked and identified, even if they change names or locations.