@Id

The `@Id` annotation is used in programming, specifically in Java’s persistence frameworks like JPA, to indicate that a particular field in a class uniquely identifies each record in a database table. Think of it as a unique label or fingerprint for each item, ensuring that each entry can be distinctly recognized and accessed. This helps the system efficiently manage data, perform updates, or retrieve specific records without confusion. Essentially, `@Id` marks the primary key property of an entity, facilitating accurate data linkage and integrity.