會計中的cost centre/ cost unit/ cost driver三者如何分？

書上的.定義：
cost centre: collecting places for costs before they are further analyzed.
cost unit: a unit of product or service to which cost can be related.
cost driver: a factor which causes a change in the cost of an activity
看定義好像都看得懂，但理解起來很吃力。能不能有比較具體透徹的解釋？