Injective is a term used in mathematics, particularly in the field of functions. A function is called injective, or one-to-one, if it assigns distinct outputs to distinct inputs. This means that no two different inputs will produce the same output, ensuring a unique mapping for each element in the domain. In practical terms, injective functions are important in various applications, including computer science and cryptography. They help in creating unique identifiers and ensuring data integrity, as each input can be traced back to a specific output without ambiguity.