When you create an employee, you have the ability to specify his/her shift (or department) name. Assigning different departments or shifts to your employees could be useful when creating payroll reports specific to certain categories of employees.
To modify a department/shift name, select if from the list and press the "Edit" button. Press "Save" to save the changes.
To adjust shift (or department) name of each employee, select the employee and go to Manage - Modify Employee Info menu.