What does Budgeted units in Expenses tab denote

Haresh,
Expenses are non-resource costs associated with a project and assigned to a project’s activities like facilities, Stationary, Administration, travel, consulting, training etc… They are typically one-time expenditures for non-reusable items and that’s why the default entry is cost and equivalent to rate/cost. You can always modify the rates and budget units for cost items that are quantifiable. Expenses cost is being manage at Project-> Expenses and cost category at Admin-> Admin Categories-> Expenses Category and cost account at Enterprise-> Cost Account.