Final answer:
The instanceof operator is used in programming languages like Java to check whether an object belongs to a specific class or implements a specific interface. The legal operands of the instanceof operator in Java are an object reference and a class or interface.
Step-by-step explanation:
The instanceof operator is used in programming languages like Java to check whether an object belongs to a specific class or implements a specific interface. In Java, the legal operands of the instanceof operator are an object reference and a class or interface. The result of the instanceof operator is true if the object is an instance of the specified class or implements the specified interface, otherwise it is false.