A circular or cyclic dependency is a situation where two or more independent modules or components rely on each other to function properly. This is referred to as mutual recursion. Circular dependency generally occurs in a modular framework while defining a dependency between modules or components.
The term circular dependency is very common across domain models where a set of objects are associated with each other. Circular dependencies between classes are not necessarily harmful. In fact, in particular situations, they are appropriate. Take an example of an application where you are dealing with domain objects such as a student and a course. You probably need a Student class that gets courses a student has enrolled in, ...
