When a customer comes knocking at the door looking for various services, how does that server know, exactly which services the customer is after?

CompTIA Network+ N10-008 is updated version of N10-007 exam.
The exam has been  reorganized to address the current networking technologies with expanded coverage of several domains by adding:

Critical security concepts to helping networking professionals work with security practitioners
Key cloud computing best practices and typical service models
Coverage of newer hardware and virtualization techniques
Concepts to give individuals the combination of skills to keep the network resilient