According to the figure, the second normal form is derived from the first normal form by further breaking two tables down into more specific units.
EMPLOYEE_TBL split into two tables called EMPLOYEE_TBL and EMPLOYEE_PAY_TBL. Personal employee information is dependent on the primary key (EMP_ID), so that information remained in the EMPLOYEE_TBL (EMP_ID, LAST_NAME, FIRST_NAME, MIDDLE_NAME, ADDRESS, CITY, STATE, ZIP, PHONE, and PAGER). On the other hand, the information that is only partly dependent on the EMP_ID (each individual employee) is used to populate EMPLOYEE_PAY_TBL (EMP_ID, POSITION, POSITION_DESC, DATE_HIRE, PAY_RATE, and DATE_LAST_RAISE). Notice that both tables contain the column EMP_ID. This is the primary key of each table and is used to match corresponding data between the two tables.
CUSTOMER_TBL split into two tables called CUSTOMER_TBL and ORDERS_TBL. What took place is similar to what occurred in the EMPLOYEE_TBL. Columns that were partly dependent on the primary key were directed to another table. The order information for a customer is dependent on each CUST_ID, but does not directly depend on the general customer information in the original table.
