A field that gives each record a unique identity is called as:

In a database, a field that uniquely identifies each record is known as a primary key. It ensures that no two records have the same value in this field and does not allow NULL values. Let's understand the options: Unique key: Ensures uniqueness but allows NULL values, so it is not the best choice for a mandatory unique identity. First key: This is not a standard database term and does not exist in database design. Primary key: Guarantees uniqueness and does not allow NULL values, making it the correct choice for uniquely identifying each record. Candidate key: Can uniquely identify records but is not the primary choice for defining a unique identity field. Therefore, the correct answer is the primary key.