A surrogate key is a type of primary key used in most database tables. It provides a simple, system-generated, business-agnostic column. This column is used as an identifier for each row rather than relying on pre-existing attributes. Learn more, including why surrogate keys are widely used, below. Before learning about surrogate keys in detail, consider reading the article “On Keys.” This will help you fully understand the concept of keys in a database model and the different types that exist.