When a business buys a new delivery truck, a patent, or an oil well, it doesn’t get to subtract the entire cost from its income on the day it writes the check. Instead, the tax code spreads that cost over several years—matching the expense to the years the asset helps produce revenue. This chapter explains the three main tools the federal tax system uses to recover capital costs: depreciation for physical things (like delivery trucks and buildings), amortization for intangible assets (like patents and customer lists), and depletion for natural resources (like oil and mineral deposits). Understanding them is essential, because even a small misstep can shift thousands of dollars between tax years and change whether a business invests, expands, or holds back.