UUID stands for Universally Unique Identifier. It is a 128-bit identifier that is globally unique and typically represented as a 32-character hexadecimal string. UUIDs are used to uniquely identify information without needing centralized coordination. They are commonly employed in various systems and applications, such as databases, distributed systems, and software development, to ensure the uniqueness of generated identifiers across different devices and platforms. The uniqueness of UUIDs is achieved through a combination of timestamp, random bits, and other factors, making collisions extremely unlikely.