Foreign Key Constraint syntax

I'm new to learning SQL syntax and came across this example in a book. I understand the need for foreign keys and using the constraint function in order to set the key to another table that is created (EMPLOYEE_TBL in this example).

My question is why it listed the line CONSTRAINT EMP_ID_FK FOREIGN KEY (EMP_ID). What exactly is the EMP_ID_FK portion? Since you just need to use the CONSTRAINT function to set a field on you child table to the parent table, couldn't you just write it as CONSTRAINT FOREIGN KEY (EMP_ID) REFERENCES EMPLOYEE_TBL (EMP_ID)); instead?

Am I understanding this incorrectly? Any help would be appreciated. Thanks!

CREATE TABLE EMPLOYEE_PAY_TBL
(EMP_ID    CHAR(9)    NOT NULL, 
DATE_HIRE   DATE   NULL,
DATE_LAST_RAISE   DATE   NULL,
CONSTRAINT EMP_ID_FK  FOREIGN KEY (EMP_ID) REFERENCES EMPLOYEE_TBL (EMP_ID));