A 5-year CD commits funds for 60 months in exchange for a fixed APY. It's the longest standard term most banks offer (a few have 7- or 10-year options, but they're uncommon), so it locks in today's rate for the longest meaningful window. In a normal upward-sloping yield curve, 5-year CDs pay the highest APY of any single CD term; in flat or inverted curves, they may pay the same or slightly less than 3-year CDs but still anchor the long end of any ladder.
Common uses: low-volatility long-term savings, a 5-year ladder's longest rung, retirement-side IRA CDs, or money earmarked for an expense roughly five years out (a college tuition payment, a planned move, a major renovation). A $10,000 5-year CD at 4.50% APY grows to about $12,461.82 over the term — roughly $2,461.82 in compound interest, more than 5× the 1-year return at the same rate because of compounding inside the CD.