Personal Finance Glossary
Plain-English definitions of APR, APY, Roth IRA, 401(k), index fund, and emergency fund — each with a short worked example and links to the DollarBrook guide or calculator that puts it to work.
APR
APY
Roth IRA
Guide: Roth IRA vs. Traditional IRA: Which One Fits You?
401(k)
Guide: 401(k) Basics and the Employer Match: Don’t Leave Free Money Behind
Index fund
Guide: Index Funds vs. Individual Stocks: A Beginner’s Honest Comparison
Emergency fund
Guide: How to Build an Emergency Fund (Even on a Tight Budget)
Frequently asked questions
What is the difference between APR and APY?
APR is the yearly cost of borrowing; APY is the yearly return on saving, including compounding. You want a low APR on your debts and a high APY on your savings.
Is a Roth IRA an investment?
No — it is an account, a container with tax rules. After contributing, you choose what to hold inside it, such as an index fund. The account and the investment are two separate decisions.
This page is educational and is not financial, tax, or legal advice. See our disclaimer.