Banks are businesses that hold and move your money, and they make profit by lending it out

A bank is a licensed financial institution that takes deposits from customers, holds that money in accounts, and lends most of it to other customers or businesses. You deposit money; the bank keeps some in reserve and lends the rest. They charge borrowers interest on loans and pay you a small amount of interest on your deposit—the difference is their profit. The bank is not a safe or a vault. It is a business that buys and sells access to money.

Banks exist because moving money between people is hard without them. If you wanted to pay someone across the country before banks, you had to physically carry cash or hire a courier. Banks created a system where you could deposit money locally, and someone else could withdraw it elsewhere. That service—plus the ability to borrow against future earnings—is what banks sell.

Key Takeaways

  • Banks profit by taking your deposits, lending most of them to borrowers at higher interest rates, and keeping the difference.
  • Your deposits are insured up to $250,000 per account type per bank by the FDIC, a federal agency that steps in if a bank fails.
  • Banks are regulated by multiple federal and state agencies that set rules about how much they can lend, what they must keep in reserve, and how they treat customers.
  • The money you deposit is not locked in a vault with your name on it—it is pooled and lent out; the bank straightforward owes you that amount.

How banks make money from your deposits

When you deposit $1,000 into a checking account, the bank does not set that $1,000 aside for you alone. It pools your deposit with thousands of others and lends most of it out. If you have a savings account earning 4% annual interest, you earn $40 per year on that $1,000. The bank lends that same $1,000 to a borrower at, say, 7% interest. The borrower pays the bank $70 per year. The bank keeps the $30 difference as profit.

This works only if enough depositors do not withdraw their money at the same time. Banks keep a fraction of deposits on hand—called the reserve requirement—and lend the rest. The Federal Reserve sets the reserve requirement, which is currently zero percent for most banks, though banks voluntarily keep reserves anyway. If a bank lends too aggressively and cannot meet withdrawal requests, it fails.

Banks also charge fees: overdraft fees, monthly account fees, wire transfer fees, ATM fees. These are direct profit with no lending involved. A bank with millions of customers paying $12 per month for an account generates substantial revenue from fees alone.

Who regulates banks and what they oversee

Banks are not free to do whatever they want. The Federal Reserve sets interest rates and reserve requirements. The Office of the Comptroller of the Currency (OCC) charters and supervises national banks. The Federal Deposit Insurance Corporation (FDIC) insures deposits and closes failing banks. State banking regulators oversee state-chartered banks. Each agency has different rules and different authority.

Regulators set capital requirements—the minimum amount of the bank's own money it must hold relative to loans it makes. They conduct audits to may support banks are not taking excessive risk. They set rules about lending discrimination, so banks cannot refuse loans based on race, religion, or other protected characteristics. They also set rules about how banks must disclose fees and interest rates to customers.

When a bank fails, the FDIC takes over. It pays depositors up to $250,000 per account type per bank from an insurance fund. If you have $300,000 in a savings account at one bank, the FDIC covers $250,000 and you lose $50,000. If you have $250,000 in a savings account and $250,000 in a checking account at the same bank, both are covered because they are different account types.

The difference between banks, credit unions, and other financial institutions

Banks are for-profit businesses owned by shareholders. Credit unions are nonprofit cooperatives owned by their members. When a credit union makes profit, it returns it to members as lower fees or higher interest rates. Credit unions are smaller and typically serve a specific group—employees of a company, members of a profession, residents of a geographic area. They are also insured, but by the National Credit Union Administration (NCUA) instead of the FDIC, with the same $250,000 coverage.

Savings and loan associations are similar to banks but historically focused on mortgage lending. Online banks are banks without physical branches; they operate entirely through websites and apps. Investment banks help companies issue stock and bonds and do not take deposits from regular customers. Brokerage firms buy and sell stocks and bonds for customers but do not take deposits.

The key distinction is whether the institution takes deposits and makes loans to individuals. If it does, it is a bank or credit union and is insured. If it does not, it is something else and your money is not protected the same way.

What happens to your money after you deposit it

You hand over $5,000 in cash or transfer it electronically. The bank credits your account when ready—you can see the balance on your phone. But the physical cash or the electronic transfer does not sit in a vault labeled with your name. The bank has received a liability: it now owes you $5,000 on demand.

Within hours, that money is likely already lent out. A small business borrows $4,500 of it at 8% interest. A homebuyer borrows $3,000 of it as part of a mortgage at 6.5% interest. The bank keeps $500 in reserve. None of this money is yours anymore—it belongs to the borrowers. The bank straightforward owes you the $5,000 you deposited, and it will pay you back from the interest and fees it collects from borrowers.

If you withdraw your $5,000 tomorrow, the bank does not retrieve it from the borrowers. It pays you from its cash reserves or from new deposits coming in. The system works because withdrawals and deposits roughly balance out. On any given day, some customers withdraw money and others deposit it. The bank manages the flow.

Why banks sometimes fail and what happens to your money

A bank fails when it cannot meet withdrawal requests. This happens when too many customers withdraw at once, or when loans go bad and borrowers do not repay. If a bank lent aggressively to risky borrowers and those borrowers default, the bank loses money. If depositors lose confidence and rush to withdraw—a bank run—the bank runs out of cash even if the loans are eventually repaid.

When a bank fails, the FDIC takes control. It pays insured depositors from its insurance fund, usually within a few business days. Uninsured deposits—anything over $250,000 per account type—may be lost or recovered partially if the bank's assets are sold. The FDIC then sells the failed bank's assets to another bank or liquidates them.

Bank failures are rare in the United States because of regulation and insurance. Between 2008 and 2023, about 600 banks failed, mostly during the 2008 financial crisis. In 2023, three banks failed: Silicon Valley Bank, Signature Bank, and First Republic Bank. Depositors with balances under $250,000 lost nothing. Depositors with balances over $250,000 were covered by emergency action from the Federal Reserve and Treasury Department, not by FDIC insurance.

How banks move money between accounts and institutions

When you send money to someone at a different bank, the banks do not exchange physical cash. They use electronic networks. A transfer between two accounts at the same bank is when ready—the bank straightforward moves the balance from one account to another in its own system.

A transfer between different banks uses the Automated Clearing House (ACH) network, which is run by the Federal Reserve and private operators. ACH transfers take one to three business days. Your bank sends a message to the receiving bank saying "Customer A is sending $500 to Customer B." The receiving bank credits Customer B's account. At the end of the day, the banks settle the difference—your bank owes the receiving bank $500, which is transferred through the Federal Reserve's settlement system.

Wire transfers use a different network called Fedwire (for large transfers between banks) or SWIFT (for international transfers). Wire transfers are faster—usually same-day or next-day—but more expensive. The bank charges a fee, typically $15 to $50, because the transfer is processed when ready and the bank takes on more risk.

Frequently Asked Questions

Is my money safe in a bank?

Your money is insured up to $250,000 per account type per bank by the FDIC. If the bank fails, you get your money back. If you have more than $250,000, the amount over $250,000 is at risk. To protect large balances, spread them across multiple banks or account types.

Why do banks pay such low interest on savings accounts?

Banks pay low interest because they can borrow your money cheaply. If you earn 4% and the bank lends at 7%, the bank keeps the difference. Competition and interest rate changes affect how much banks pay. When the Federal Reserve raises rates, banks eventually raise savings rates too, but they lag behind.

Can a bank take my money if I owe a debt?

A bank can freeze your account if you owe it money directly—for example, an unpaid loan or overdraft. A creditor can also obtain a court order to freeze your account and take money to pay a judgment. The bank must follow legal procedures and cannot straightforward take money without a court order or your authorization.

What is the difference between a debit card and a credit card?

A debit card draws directly from your bank account—you spend money you have. A credit card borrows money from the card issuer, and you pay it back later with interest. Debit cards offer less fraud protection than credit cards in most cases, though federal law limits your liability for both.

Do I need a bank account?

You do not legally need a bank account, but it is difficult to function without one in modern life. Employers usually require direct deposit. Landlords require a way to collect rent. Utilities require a payment method. Some people use prepaid cards or check-cashing services instead, but these charge higher fees than banks.