Describe generalizing actors

What will be an ideal response?

An actor is an abstraction of real users. "Customer" generalizes selected attributes of real people who purchase goods and/or services from a business. But even these abstract entities may need to be generalized further if they share the same role with other actors in a use case: in conducting the affairs of an airplane, the captain and assistant pilot have distinct roles, but when one of them has the controls and actually flies the plane, it is one primary actor, Pilot, who follows the script of a Fly Boeing 747 use case.
Sometimes, however, we end up with generalized actors through a reverse process: specialization. Through expanding use cases and gathering requirements, we may find that an existing role is appropriate for certain use cases, but not others: during pre-flight check of the airplane, Pilot is not enough; Chief Pilot is needed to read off the checklist and Assistant Pilot is needed to check off the items.