Difference between exposure unit and a platesetter

Hi everyone, this is my first post here. As someone who has come from a screenprinting background, can anyone describe the difference between an exposure unit and platesetter?

What is the difference?

 

well it is simply different technology to do the same - plates
An expo' unit will use UV light , film and UV sensetive plates - the old way
Plate setter / CTP will use a light beem and a plate sensetive to the kind off beem used (i.e. red laser / thermal , green laser...) - this is the latest technology , since 1998.....
Today , the old tech is cheaper to buy but expensive to run
while the new tech is more expensive to buy and cheaper to run

How can i help biond this ?