cost component

hi,

may i know what is cost component structure

BH (component cogs)

BP (primary cost component).

1) what is cost component? the type of cost?

2) the cost component list for each BH and BP is made up of BH and BP? example BH, all the cost component in the list is cogs related component?

3) what does it mean primary cost component? can have example?

4) i see some of the cost component in both BH and BP. why.

thanks