A classification is a way of identifying an employee's pay rate within a single award.
Example An award for chef's may be called a Chef's Award. However, there would be several levels within this award. It would probably contain:
Apprentice Chef – Year 1
Apprentice Chef – Year 2
Apprentice Chef – Year 3
Apprentice Chef – Year 4
Chef – Level 1
Chef – Level 2
Chef – Level 3