When property is depreciated, the basis of the property is reduced by the amount of depreciation taken. If the sale price is larger than amount of depreciation that has been taken, the difference will be reported as either ordinary income or capital gain, depending on the type of property that is sold.
For example, suppose that Frank buys business equipment for $10,000 and uses it for eight years. The total depreciation deduction is $6,000. Then he sells the equipment for $6,000. He must declare a "recaptured" gain of $2,000, the difference between the actual sales price and the depreciated tax basis of $4,000 ($10,000-$6,000).