The 'typeof' operator in JavaScript is used to return a string indicating the type of the operand.
The 'instanceof' operator in JavaScript is used to check the current object and returns true if an object is an instance of a particular class or constructor.
The 'typeof' operator is used when you want to know the type of a primitive value.
The 'instanceof' operator is used when you want to know if an object is an instance of a certain class.