Final answer:
The 'return' statement is used in a method to specify the value that it gives back to the caller, which must match the method's declared return type.
Step-by-step explanation:
The statement used to specify the value that a method gives back to its caller is the return statement. When a method needs to send a result back to the line of code that invoked it, the return keyword is used followed by the value to be returned. This can be a variable, an expression, or a literal value. The returned value must match the method's declared return type.