TLDR:
Amortization is the process of gradually writing off the initial cost of an intangible asset over its useful life (in accounting) or paying off a loan through scheduled payments over time (in finance).
Amortization in Finance
A loan amortization schedule shows the breakdown of each payment into principal and interest over the loan term.
Amortization in Accounting
Intangible assets like patents, trademarks, and software are amortized over their useful lives, similar to depreciation for tangible assets.