What is the difference between overhead allocation with overhead apportionment?

The following are the differences between allocation and apportionment.

1. Allocation costs are directly allocated to cost centre. Overhead which cannot be directly

allocated are apportioned on some suitable basis.

2. Allocation allots whole amount of cost to cost centre or cost unit where as apportionment

allots part of cost to cost centre or cost unit.

3. No basis required for allocation. Apportionment is made on the basis of area, assets

value, number of workers etc.