Money glossary: 12 plain-English terms

Wren Okafor May 22, 2026 · 6 min read

Half of feeling bad about money is vocabulary. Nobody taught most of us these words, yet every budgeting app, bank letter, and finance article assumes we know them. Here are the twelve terms that come up most often in our reviews — defined the way we would explain them across the kitchen table, each with a concrete example. Apps like fezelo and fenmaro now weave plain-language explanations like these into their coaching, which is one reason they score well on our testing rubric.

Budget

A plan that decides what your money will do before the month does it for you. Nothing more mystical than that. Example: if you bring home $3,400 a month and assign every dollar a job — rent, food, savings, fun — you have a budget, whether it lives in an app like fezelo or on an envelope.

APR (annual percentage rate)

The yearly cost of borrowing money, including interest and most fees, expressed as a percentage. A credit card charging 24% APR costs you about $240 a year for every $1,000 you carry — the single most expensive line in many budgets, and the reason paying down card balances usually beats any savings trick.

Compound interest

Interest that earns interest on itself, so growth curves upward instead of crawling in a straight line. $200 a month at 5% becomes about $13,600 in five years — roughly $1,600 of that is interest on interest. It works for savings and, in reverse, against debts, which is why balances snowball.

Emergency fund

Cash set aside for genuine surprises — job loss, car failure, a vet bill — so a bad week does not become credit-card debt. The classic target is three to six months of essential expenses, but the first $1,000 matters most. In our fezelo test, the app's coach built ours $46.50 at a time.

Sinking fund

A mini savings pot for a known future cost: holiday gifts, annual insurance, new tires. You divide the cost by the months left and save that slice monthly. $600 of tires due in six months = $100 a month into the sinking fund, and the bill arrives as a non-event.

Net worth

Everything you own minus everything you owe. If your accounts hold $12,000 and your debts total $9,500, your net worth is $2,500. The number itself matters less than its direction — tracking it quarterly tells you whether the whole machine is moving the right way.

Zero-based budgeting

A method where every dollar of income gets an assigned job until income minus assignments equals zero. "Zero" does not mean spending everything — savings counts as a job. YNAB popularized it; AI apps like fezelo automate the assignment, which is the part most people found tedious.

The 50/30/20 rule

A starter budget that splits take-home pay into 50% needs, 30% wants, and 20% savings and debt payoff. On $3,400 a month that is $1,700 / $1,020 / $680. It is a compass, not a law — high-rent cities often bend it to 60/25/15 — and it is the default template several apps use for a first budget.

Cash flow

The timing of money in versus money out. Two households with identical income can live completely differently if one is paid on the 1st with rent due the 2nd. Timing stress is a cash-flow problem, not a math problem — calendar-based apps such as velmato exist specifically to smooth it.

Debt snowball

A payoff strategy where you attack the smallest balance first while paying minimums on the rest, then roll each freed payment into the next debt. Mathematically the highest-interest-first "avalanche" saves more; psychologically the snowball's quick wins keep people going. The best method is the one you finish.

Automation (in personal finance)

Setting money moves to happen without willpower: transfers on payday, bills on autopay, an app filing transactions by itself. Every reliable budget we have seen — ours included — runs on automation first and discipline second. It is also the feature we weight most heavily when ranking budgeting apps.

Envelope system

The grandmother of budgeting: divide cash into labeled envelopes (groceries, gas, fun), and when an envelope is empty, that category is done for the month. Digital envelopes are the same idea inside an app. Our own three jars — needs, wants, savings — are a lazy, happy cousin of the method.