Table:
|  | Amortized Cost | Fair Value |
| --- | --- | --- |
| Within 1 year | $6,322 | $6,324 |
| After 1 year through 5 years | 12,191 | 12,218 |
| After 5 years through 10 years | 1,643 | 1,687 |
| After 10 years | 9 | 10 |
| Mortgage-backed securities with no single maturity | 1,425 | 1,421 |
| Total | $21,590 | $21,660 |
Paragraphs:
The following table summarizes the maturities of our available-for-sale debt investments as of July 27, 2019 (in millions):
Actual maturities may differ from the contractual maturities because borrowers may have the right to call or prepay certain obligations.
Question:
Why would actual maturities differ from the contractual maturities?
Answer: borrowers may have the right to call or prepay certain obligations.