Explain the concept of default methods in interfaces.

Default methods in interfaces, introduced in Java 8, revolutionized the way interfaces are used in Java. They allow interfaces to contain method implementations, marked with the ‘default’ keyword, providing a solution to the problem of evolving interfaces without breaking existing implementations. With default methods, interfaces can define method implementations directly within the interface itself, enabling backward compatibility with existing implementations. Classes that implement the interface can choose to override the default method with their own implementation or inherit the default implementation provided by the interface. This flexibility allows for the addition of new methods to interfaces without forcing changes to all implementing classes. Default methods also introduce a form of multiple inheritance in Java, as interfaces can now provide common behavior that can be shared by multiple classes. Overall, default methods in interfaces provide a powerful mechanism for evolving interfaces over time while maintaining backward compatibility and enabling code reuse.