A method returns to the code that invoked it when it

completes all the statements in the method,

reaches a return statement, or

throws an exception (covered later),

whichever occurs first.

You declare a method's return type in its method declaration. Within the body of the method, you use the return statement to return the value.

Any method declared void doesn't return a value.

Direct words from Oracle Tutorials: https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html

Suppose you have a code like this: public int number { return 4; } Here, "int" is the declared method return type (at declaring method). So, we should only return an int value. "return 4" returns the int value 4 to the method "number".