I read the post... it's not fully defined but certainly makes a swag at the differences. I'm assuming this was specific to your area/company... ? 
 
 
 
I'm Strategy & Design for a Global Service Desk with 10+ years experience, I'd be happy to commment more should you have questions.

These were difference I gleaned from various white papers and academic papers about customer support and help desks published in the United States.  
 
I know that many use these terms interchangeably but that can certainly confuse things between business and vendors, designers and users, etc. 
 
One take-away is certainly to define exactly what you want to accomplish before putting a system into place and then make certain everyone is on the same page. 
 
Also, I am genuinely interested in how most people view these terms. Our company is a provider of customer service and support solutions for the SMB market. What would be your definitions of these terms and what region are you in?