Money Basics: Save, Borrow & Invest

Most money decisions come down to a handful of ideas: interest (what money costs or earns over time), risk, and fees.

These explainers cover saving, borrowing and investing basics, with examples from India and elsewhere. They explain how things work; they are not personal financial advice.

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How does refinancing work?

Refinancing means replacing an existing loan with a new one, usually to get a lower interest rate, smaller payments, or different terms. You take out a new loan to pay off the old one — common with mortgages when rates drop.

How do savings accounts work?

A savings account works by holding your money safely at a bank while paying you interest on the balance. The bank uses your deposits to lend to others, and in return pays you a small percentage, helping your money grow gradually over time.

How does a fixed deposit work?

A fixed deposit works by lending your money to the bank for a fixed term. The bank uses it and pays you a guaranteed interest rate in return; the longer the term, usually the higher the rate. At maturity you get your original amount back plus the interest earned.

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How does compound interest work?

Compound interest works by paying interest on both your original money and the interest it has already earned. Each period the balance grows a little more, and that larger balance earns even more next time — accelerating growth.

How does a loan work?

A loan works by a lender giving you a sum of money now that you repay over time, plus interest — the cost of borrowing. You typically repay in regular installments that cover both the original amount (principal) and the interest.

How does a mortgage work?

A mortgage works as a long-term loan used to buy a home, where the property itself is the collateral. You repay it in monthly installments over many years, covering both the amount borrowed and interest — and the lender can take the home if you don't pay.

How does a credit score work?

A credit score works as a number that predicts how likely you are to repay borrowed money. Lenders calculate it from your history of paying bills, debts, and loans — and use it to decide whether to lend to you and at what interest rate.

How does a credit card work?

A credit card lets you borrow money from a bank, up to a limit, to pay for things and repay later. The bank pays the merchant instantly; you repay the bank — interest-free if you clear the balance by the due date, with interest if you don't.

How does a checking account work?

A checking account is a bank account built for everyday spending. You deposit money and can withdraw or pay from it anytime — using a debit card, transfers, or checks. It's designed for frequent access rather than earning interest.

How does budgeting work?

Budgeting works by planning how to spend your money before you spend it. You track income and expenses, set limits for different categories, and adjust so you spend less than you earn — leaving room to save and reach your goals.

How does inflation happen?

Inflation happens when overall demand for goods and services outpaces supply, or when the money supply grows faster than the economy — so more money chases the same goods, and prices rise.

How does UPI work?

UPI (Unified Payments Interface) lets you send money instantly between bank accounts using just a phone. You link your bank to an app, pay with a UPI ID or by scanning a QR code, enter a secret PIN, and the money moves bank-to-bank in seconds — no card or account number needed.

How does online banking work?

Online banking works by securely connecting you to your bank's systems over the internet. After you log in — usually with a password plus extra verification — encryption protects your data as you check balances, pay bills, and transfer money.

How does a bank work?

A bank works by taking in deposits and lending most of that money out at interest, making a profit on the gap. It keeps your money safe and accessible while channeling savings into loans for homes, businesses, and spending.

How does insurance work?

Insurance works by pooling risk. Many people pay regular premiums into a shared fund, and when one of them suffers a covered loss, the insurer pays out from that pool. You trade a small, certain cost for protection against a large, uncertain one.

How do mutual funds work?

A mutual fund pools money from many investors and a professional manager uses it to buy a diversified mix of stocks, bonds, or other assets. Each investor owns shares of the fund, sharing in its gains and losses — an easy way to diversify.

How does index investing work?

Index investing means buying a fund that simply tracks a whole market index, like the S&P 500, instead of trying to pick winning stocks. You get broad diversification at low cost, matching the market's overall return rather than beating it.

How does dollar-cost averaging work?

Dollar-cost averaging means investing a fixed amount at regular intervals, no matter the price. You buy more shares when prices are low and fewer when high, smoothing out your average cost and reducing the risk of badly timing the market.

How does retirement investing work?

Retirement investing works by regularly putting money into investments — like funds holding stocks and bonds — over your working life, letting compound growth build a large nest egg. Tax-advantaged accounts and starting early make the biggest difference.

How do pensions work?

A pension works by setting aside money during your working years so you have income after you retire. You (and often your employer) contribute regularly; the money is invested and grows, then pays you a regular income in retirement.

How does the stock market work?

The stock market works by matching buyers and sellers of company shares on exchanges. Prices move continuously based on supply and demand, which reflect investors' changing expectations about each company's future.

How do bonds work?

A bond is essentially a loan you give to a government or company. In return, they pay you regular interest for a set period, then repay the original amount at the end. Bonds are usually steadier and lower-risk than stocks.

How do dividends work?

A dividend is a share of a company's profit paid out to its shareholders, usually as cash. If you own stock in a dividend-paying company, you receive regular payments — a way to earn income from investments without selling them.

How do taxes work?

Taxes work by governments collecting a share of income, purchases, or property to fund public services like roads, schools, and healthcare. The amount you owe depends on rules such as income brackets, deductions, and the type of tax.

Key ideas behind them

What is an EMI (equated monthly installment)?

An EMI, or equated monthly installment, is the fixed amount you pay every month to repay a loan — covering both the borrowed principal and the interest. It lets you buy something big now (a phone, a bike, a home) and spread the cost over months or years.

What is a fixed deposit?

A fixed deposit (FD) is money you lock with a bank for a set period at a guaranteed interest rate. You can't touch it until it matures, and in return the bank pays you more interest than a regular savings account — a safe, predictable way to grow savings.

What is a SIP (systematic investment plan)?

A SIP, or systematic investment plan, is a way to invest a fixed amount in a mutual fund automatically every month instead of all at once. It builds the habit of investing, averages out market ups and downs, and turns small regular amounts into a large corpus over time.

What is a mutual fund?

A mutual fund pools money from many investors to buy a diversified mix of stocks, bonds, or other assets, managed by professionals. It lets ordinary investors own a slice of a broad portfolio without picking each investment themselves.

What is an IPO?

An IPO (Initial Public Offering) is when a private company sells shares to the public for the first time, becoming a publicly traded company. It raises money for the business and lets everyday investors buy a stake.

What is a credit rating?

A credit rating is an assessment of how likely a borrower — often a government or company — is to repay its debt. Agencies like Moody's and S&P assign grades (such as AAA down to junk); higher ratings mean lower risk and cheaper borrowing.

What is a credit score?

A credit score is a three-digit number (in India, 300–900) that sums up how reliably you repay borrowed money. Lenders use it to decide whether to give you a loan or credit card — and at what interest rate. A higher score means cheaper, easier credit.

What are interest rates?

An interest rate is the cost of borrowing money — or the reward for saving it — expressed as a percentage. It's how much extra a borrower pays a lender over time, and it shapes everything from loans to the wider economy.

What is an emergency fund?

An emergency fund is money set aside to cover unexpected expenses — like a job loss, medical bill, or car repair — without going into debt. Experts often suggest saving three to six months of living costs in an easily accessible account.

What is net worth?

Net worth is what you own minus what you owe — your total assets (cash, investments, property) less your total debts. It's a single snapshot of your financial health, and growing it over time is a core goal of personal finance.

What is the Rule of 72?

The Rule of 72 is a quick mental shortcut to estimate how long it takes money to double at a given interest rate. Just divide 72 by the annual rate: at 8% interest, money doubles in about 72 ÷ 8 = 9 years.

What is amortization?

Amortization is paying off a debt over time in regular, equal installments that cover both interest and principal. Early payments go mostly to interest, while later ones chip away more at the original amount borrowed.

What is GST (Goods and Services Tax)?

GST, or Goods and Services Tax, is a single indirect tax India charges on most goods and services. It replaced a tangle of older taxes with one nationwide system, so the same product is taxed the same way across every state.

What is income tax?

Income tax is a tax governments charge on the money people and businesses earn. It funds public services like roads, schools, and healthcare, and usually rises with how much you earn.

Frequently asked questions

What is the difference between simple and compound interest?

Simple interest is paid only on the original amount. Compound interest is also paid on interest you have already earned, so the balance grows faster the longer it is left alone.

How is an EMI calculated?

An EMI spreads a loan's principal and interest into equal monthly payments using the loan amount, the interest rate and the number of months. Early payments are mostly interest; later ones are mostly principal.

When is refinancing worth it?

Generally when the new loan's lower rate or better terms save more than the fees and costs of switching over the time you expect to keep the loan.