Banks are businesses that hold your money and lend it out to earn profit

A bank is a company licensed by the government to take deposits from customers, keep that money safe, and lend it to other people and businesses. When you put money in a bank account, the bank doesn't lock your cash in a vault with your name on it. Instead, the bank uses your money — along with deposits from thousands of other customers — to make loans. The bank pays you a small amount of interest (a percentage of your balance) for letting them use your money, and charges borrowers a higher interest rate on their loans. The difference between what the bank pays you and what it charges borrowers is how the bank makes profit.

This arrangement works because most customers don't withdraw all their money at once. A bank might have $10 million in deposits on any given day, but only $500,000 of actual withdrawals happening. That means the bank can safely lend out $8 million or more, knowing it will have enough cash on hand for the withdrawals that actually occur. If too many customers try to withdraw money at the same time — an event called a "bank run" — the bank can run out of cash even if it owns valuable assets. This is why the government insures deposits and regulates how much banks can lend.

Key Takeaways

  • Banks make money by borrowing from depositors (you) at a low interest rate and lending to borrowers at a higher rate.
  • Your deposits are insured by the Federal Deposit Insurance Corporation (FDIC) up to $250,000 per account type at each bank, protecting you if the bank fails.
  • Banks must keep a portion of deposits on hand and cannot lend out every dollar customers deposit.
  • The government regulates banks to prevent them from taking excessive risk with customer money.
  • Different types of banks — commercial banks, credit unions, online banks — operate under the same basic model but may offer different services and fees.

How your deposit moves through the banking system

When you deposit a check or transfer money into your account, the bank doesn't when ready have access to those funds. If you deposit a check, the bank must first verify that the check is real and that the account it's drawn on has enough money. This process is called check clearing, and it typically takes one to three business days. During that time, the money is in transit between banks, being verified at each step.

For electronic transfers — like a direct deposit from your employer or a wire transfer — the process is faster because the money moves directly between bank computers. Your employer's bank sends a message to your bank saying "move $2,000 from this account to that account," and the transfer usually completes within one business day. Once the money arrives in your account, it belongs to you, but the bank still controls it. You can withdraw it, spend it, or transfer it, but the bank holds the actual funds and uses them for lending until you ask for it back.

Why banks charge fees and what they're paying for

Banks charge fees for services because they cost money to provide. A monthly maintenance fee pays for the staff who answer phones, the computers that process your transactions, the buildings where branches operate, and the security systems that protect customer data. When you use an out-of-network ATM and pay a fee, you're paying both your bank (for allowing the transaction) and the other bank (for letting you use their machine). Overdraft fees happen when you spend more money than you have in your account — the bank covers the difference as a short-term loan and charges you for that service.

Not all banks charge the same fees, and some charge none. Online banks often have lower fees because they don't operate physical branches. Credit unions, which are member-owned rather than profit-driven, frequently charge lower fees than commercial banks. The fees you pay are negotiable — if your bank charges high fees and you have a good history, you can sometimes ask them to waive fees or switch to an account type with lower costs.

How banks decide whether to lend you money

When you explore for a loan or credit card, the bank uses your credit report and credit score to decide whether to lend to you and at what interest rate. Your credit report is a record of your borrowing history — every loan you've taken, every credit card you've opened, and whether you paid on time. Your credit score is a number (typically between 300 and 850) that summarizes that history. A higher score means you've paid bills on time consistently, so the bank sees you as lower risk.

Banks also look at your income and existing debts. If you earn $40,000 a year and already owe $30,000 in student loans and car payments, a bank may decide you can't safely borrow more. This calculation is called your debt-to-income ratio. For a mortgage or large loan, the bank will also verify your income by asking for recent pay stubs or tax returns, and may order an appraisal of the property you're buying. All of this takes time and costs the bank money, which is why banks charge process fees for mortgages and other large loans.

What happens when a bank fails

Bank failures are rare in the United States because of federal regulation and deposit insurance. The Federal Deposit Insurance Corporation (FDIC) insures deposits at member banks up to $250,000 per account type at each bank. This means if your bank fails, the FDIC will pay you back up to $250,000 from a fund supported by banks themselves, not taxpayers. Account types are insured separately — your checking account, savings account, and money market account are each insured up to $250,000, so you could have $750,000 total protection at one bank.

When a bank fails, the FDIC typically arranges for another bank to buy it and take over customer accounts. Your account transfers to the new bank, and you keep access to your money. In rare cases where no bank wants to buy the failed bank, the FDIC pays depositors directly. This process usually takes a few weeks. Credit unions have similar protection through the National Credit Union Administration (NCUA), which insures deposits up to $250,000 per account type.

The difference between banks, credit unions, and online banks

Commercial banks are for-profit companies owned by shareholders. They operate physical branches, offer a wide range of services (checking, savings, loans, investment accounts), and typically charge fees. Credit unions are non-profit organizations owned by their members. You must meet membership requirements (like working for a specific employer or living in a certain area) to join, but members often receive lower fees, higher interest rates on savings, and lower rates on loans. Credit unions are smaller than banks and may have fewer branches and ATMs.

Online banks have no physical branches — you manage your account through a website or app. Because they have lower overhead costs, online banks typically offer higher interest rates on savings accounts and lower or no monthly fees. The tradeoff is that you can't walk into a branch to deposit cash or speak to someone in person. Online banks usually allow deposits through mobile check deposit (taking a photo of a check with your phone) or transfers from other banks. All three types are insured the same way and operate under the same basic model: they take deposits, lend money, and charge fees for services.

How interest rates work and why they change

The interest rate a bank pays you on savings depends on the federal funds rate, which is the interest rate the Federal Reserve (the central bank of the United States) charges banks when they borrow from each other. When the Federal Reserve raises this rate, banks have to pay more to borrow, so they raise the interest rates they offer on savings accounts to attract deposits. When the Federal Reserve lowers the rate, banks lower the interest they pay you. This is why the interest rate on your savings account might go up or down even though you haven't changed anything.

The interest rate a bank charges on loans works the opposite way — when the Federal Reserve raises rates, banks charge borrowers more. This is why mortgage rates, car loan rates, and credit card rates all tend to move together. Banks also adjust rates based on risk: a borrower with a high credit score gets a lower rate than a borrower with a low score, because the low-score borrower is more likely to default. The difference between the rate the bank pays you and the rate it charges borrowers is called the spread, and it's where the bank makes most of its profit.

How banks protect your money and your information

Banks use multiple layers of security to protect customer deposits and data. Physical security includes vaults, cameras, and armed guards at branches. Digital security includes encryption (scrambling data so only authorized people can read it), firewalls (software barriers that block unauthorized access), and fraud monitoring systems that flag unusual transactions. Banks also require passwords and, increasingly, two-factor authentication (a second verification step, like a code sent to your phone) to access accounts online.

If someone fraudulently uses your debit card or account number, federal law limits your liability. If you report the fraud within two business days, you're responsible for at most $50 of unauthorized charges. If you wait longer, your liability can go up to $500. If you report it after 60 days, you could lose all the money in your account. This is why it's important to check your account regularly and report suspicious activity quickly. Banks also have insurance and legal obligations to investigate fraud, so they have incentive to catch it.

Frequently Asked Questions

Where does the money go when I deposit it?

The bank adds the amount to your account balance, which is a record of how much money you own at that bank. The actual cash or electronic funds are mixed with deposits from other customers and used for loans, investments, and operating expenses. You don't get the same physical dollars back — you get the equivalent value whenever you withdraw.

Can a bank take my money if it needs it?

No. Your deposits are your money, and the bank cannot use them without your permission. Banks are required by law to keep enough cash on hand to cover normal withdrawals. If a bank runs out of cash due to poor management, the FDIC steps in and pays you back up to $250,000 per account type.

Why do some banks offer higher interest rates than others?

Online banks and credit unions typically offer higher rates because they have lower operating costs. Banks also raise rates when they need more deposits to fund loans. During periods when the Federal Reserve raises interest rates, all banks tend to raise their rates, but the amount varies by bank and account type.

What's the difference between a debit card and a credit card at a bank?

A debit card draws money directly from your checking account — you can only spend what you have. A credit card is a loan from the bank that you pay back later. Banks issue both, but they work differently. Debit cards have fraud protection; credit cards build your credit history if you pay on time.

Do I need to use a bank, or can I keep cash at home?

You don't have to use a bank, but banks offer safety (FDIC insurance), convenience (ATMs, online access), and the ability to build credit. Cash at home is not insured if it's lost or stolen. For most people, a bank account is safer and more practical than keeping large amounts of cash.