Any entity or object that consists of parts, each of which hasa relationship with all other parts and the entity as a whole, is called a functional dependency.
Step-by-step explanation:
Functional dependency can be defined as a relationship between two or more attributes of an entity. In other words, an attribute is defined with the help of the value of another attribute.
An attribute uniquely defines the value for other attributes in case of existence of functional dependencies. For example, the age attribute of an entity can determine whether the individual can vote or not.