Cost elements: Primary & Secondary

Cost center is a cost element classifies the organization's valuated consumption of production factors within a controlling area.
Cost center is an organizational unit within a controlling area that represents a defined location of cost incurred. It can be defined based on various criteria such as functional requirements, allocation criteria,physical location etc. 

Primary Element - 
Primary costs that originate outside the company; relate directly to the income statement in FI and must be 
included in the FI Chart of Accounts.
All Primary cost elements gets linked to Income statement.

Secondary Element - 
Secondary costs that result from internal allocation activities; NO relation to G/L accounts in FI. These 
accounts are exclusively for cost accounting and are only maintained in CO.