Definition: Allocations divide costs between different departments or activities within a company. For instance, overhead costs such as the rent and utilities are often allocated to the company's operating units. Determining accruals and allocations nearly always entails making assumptions and estimates.
In simple terms you can say that acquisition is an act of one company taking over or acquiring another company's controlling interest. This can be done either by buying assets of that company or buying shares or stocks of the company.