Accelerated depreciation refers to any one of several methods by which a company, for 'financial accounting' or tax purposes, depreciates a fixed asset in such a way that the amount of depreciation taken each year is higher during the earlier years of an asset's life. For financial accounting purposes, accelerated depreciation is expected to be much more productive during its early years, so that depreciation  expense will more accurately represent how much of an asset's usefulness is being used up each year.
Accelerated depreciation encompasses various strategies for companies to depreciate long-term assets faster by allocating larger costs during the initial years of an asset's existence. For financial accounting purposes, accelerated depreciation tends to be more effective in its early stages, thereby providing a truer representation of how much utility from the asset is being utilized each year.