Functional Dependency is a concept in database design that describes a relationship between two attributes, typically within a relational database. It occurs when the value of one attribute, known as the determinant, uniquely determines the value of another attribute. For example, if we have a table of students, the student ID can determine the student name, meaning that each student ID corresponds to exactly one student name. In formal terms, if we say that attribute A functionally determines attribute B, we write it as A → B. This relationship is crucial for ensuring data integrity and helps in organizing data efficiently. Understanding functional dependencies aids in the process of normalization, which reduces redundancy and improves data consistency in databases.