What is Comparable and Comparator interface ? List their differences.

Java provides the Comparableinterface, --> which contains only one method, called compareTo. 

1. This method compares two objects, in order to impose an order between them. Specifically, it returns a negative integer, zero, or a positive integer to indicate that the input object is less than, equal or greater than the existing object. 

Java provides the Comparator interface, --> which contains two methods, called compare and equals. 

1. The first method compares its two input arguments and imposes an order between them. It returns a negative integer, zero, or a positive integer to indicate that the first argument is less than, equal to, or greater than the second. 
2. The second method requires an object as a parameter and aims to decide whether the input object is equal to the comparator. The method returns true, only if the specified object is also a comparator and it imposes the same ordering as the comparator.