CSAT or CSat is a term frequently used in the field of marketing & customer care, what does it?

It is the measure or yard stick by which you get to know the amount of satisfaction customer has got against the service offered.

it usually refers to customers satisfaction score 

customer satisfaction (CSAT) is a measure of the degree to which a product or service meets the customer's expectations.

Its a customer satisfaction score. Normally used in gauging and monitoring customer care performance.

Very frequently used in almost all industries.  

Thank you for the invitation. I agree with the experts answers.