In terms of financial analysis, Depreciation and Amortization is considered an expense. Depending on the asset and what accounting rules the company may be operating under, an asset can be depreciated over multiple reporting periods.
Amortization of a loan also happens over many reporting periods and is the reason they are often included with depreciation. Careful investors may want to identify the amounts of each, as these values are often explained in further detail in the accompanying notes to the financial statements.