In any discussion about customer experience, the idea of service comes up in many forms. Who is responsible for customer service? (Everyone.) When should it start. (Right away.)
To easily define the difference, I look at it this way.
Customer Service = Reactive
Customer Experience = Proactive
Service departments are created as a way to handle the input from customers. The reps are trained to respond to customer requests, questions and complaints. The idea of customer service really starts after purchase.
The Experience is something much broader and more proactive. The way the experience is designed, maintained and nurtured is what leads to happy customers. They respond to the experience you present to them, not the other way around.
These are my explanations. How do you define the difference?