1) Future cost and historical cost: financial decision is based on the future cost and not on the historical cost. The decision related to the future and hence the cost are likely to be incurred in furthered costs.
2) Specific cost and composite costs: the cost of individual source of the capital of all the sources combined in the terms as composite cost or overall cost. It is thus the weighted cost thus. the cost of debenture and preference shares equity shares and retained earnings is to be secretly calculated first and then combined cost can be computed since the combined cost consider the quantum of the financing through each cost the cost is known as the weighted cost. It is this overall which is the important in the evaluating of a firm as on ongoing entity. The composite cost of capital is the cost which is to be considering while the evaluating capital project also. In case only one source of financing is to be used for the investment proposal the specific cost of that source of that funds may be consider but in a capital structure decision, it is always the weighted cost of capital that is significant.