What are the main characteristics of functional dependencies that are used for normalization?

Functional dependencies describe the relationship between attributes in a relational database, indicating that the value of one attribute (or a set of attributes) determines the value of another attribute. The main characteristics include completeness, where every attribute is functionally dependent on the primary key; irreducibility, meaning the dependencies cannot be simplified without losing information; and non-transitivity, which ensures that dependencies do not imply others that aren't explicitly stated. These characteristics guide the normalization process, helping to eliminate redundancy and maintain data integrity.