book value

The book value of an asset is the amount of cost in its asset account less the accumulated depreciation applicable to the asset.
The book value of a company is the amount of owner's or stockholders' equity.
The book value of bonds payable is the combination of the accounts Bonds Payable and Discount on Bonds Payable or the combination of Bonds Payable and Premium on Bonds Payable.
To learn more, see Explanation of Depreciation.