Throttle body service? on 2004 Chrysler Town & Country

What do the dealers mean when they say "throttle body service'?
What is the throttle body?

1 answer
Here is some info that will help to explain what it is and why it should be serviced
http://repairpal.com/throttle-body
http://repairpal.com/throttle-body-service
http://en.wikipedia.org/wiki/Throttle_body