Final answer:
A service mark is used to identify the source of a service and differentiate it from others. It helps protect and differentiate services provided by businesses.
Step-by-step explanation:
A service mark is used to identify the source of a service. It distinguishes the services of one provider from those of another. The purpose of using a service mark is to protect and differentiate services offered by businesses. It helps consumers to easily recognize and associate a particular service with a specific provider.