Allocation and Apportionment of Cost

ALLOCATION OF COST: allocation of cost is a process by      which
cost items are charged directly to the cost center. for example:  electricity
charges can be allocated to various departments if separate meters are 
installed, salary of stores clerk can be allocated to stores department etc. 

APPORTIONMENT OF COST:  now apportionment of cost is a process
where u cant easily identify a cost to a particular cost or service center,
for example if there is single electricity meter for the all department, 
then it becomes a little difficult to allocate the exact cost to a cost
center, another example rent will have to be apportioned to various 
departments on the basis of floor space.