What Is a Bank and How Does It Work?

A bank is a licensed financial institution that accepts deposits, makes loans, and processes payments. It works by pooling money from depositors and lending it out at a higher interest rate, earning the difference. This explanation covers how banks operate, the main types, how they make money, and how regulation protects customers, using the Central Bank of Nigeria (CBN) as a concrete example of how the system is structured.

Core Functions of a Bank

At its most basic, a bank performs three jobs:

• Taking deposits – Customers place money in savings or current accounts. The bank holds it and owes it back on demand.
• Making loans – The bank lends a portion of those deposits to individuals and businesses, charging interest.
• Processing payments – Banks move money between accounts, handle transfers, clear cheques, and connect to payment networks.

These three functions are interlinked. Deposits provide the funds for lending, and payment processing keeps money circulating through the economy.

How Banks Earn Money

Banks primarily profit from the interest rate spread — the gap between the interest they pay depositors and the interest they charge borrowers.

A bank's profitability depends on managing risk: if too many borrowers default, the spread shrinks or turns into a loss.

Types of Banks and Financial Institutions

Not every institution that handles money is a bank. The roles differ significantly:

Commercial Banks

These are the banks most people use daily. They accept deposits from the public, make loans, and offer current accounts, savings accounts, and payment services. In Nigeria, commercial banks are licensed and regulated by the CBN.

Central Banks

A central bank does not serve individual customers. Instead, it manages the entire banking system. The Central Bank of Nigeria (cbn.gov.ng) is the country's apex monetary authority. Its responsibilities include:

• Issuing legal tender (the naira)
• Setting monetary policy and interest rates
• Supervising and regulating banks and other financial institutions
• Managing foreign exchange reserves
• Publishing macroeconomic data such as inflation rates and foreign exchange details

The CBN's website is a primary source for Nigeria's macro indicators, latest news, and regulatory documents.

Other Financial Institutions

• Microfinance banks – Serve small businesses and low-income customers with smaller loans.
• Development banks – Fund infrastructure and long-term projects.
• Credit unions (cooperatives) – Member-owned, not-for-profit, and typically offer better rates to members than commercial banks.
• Fintech providers – Apps and platforms that offer payments, transfers, or lending, often built on top of licensed bank infrastructure.

How Regulation and Deposit Insurance Protect Customers

Banks operate under strict regulation because they hold the public's money. Key protections include:

• Licensing – A bank must be licensed by the central bank before it can accept deposits. In Nigeria, the CBN grants and revokes these licences.
• Prudential requirements – Banks must maintain minimum capital levels and liquidity ratios to absorb losses.
• Deposit insurance – Schemes such as the Nigeria Deposit Insurance Corporation (NDIC) protect depositors up to a set limit if a bank fails.
• Supervision – Regular examinations and reporting requirements ensure banks follow the rules.

These safeguards exist because a bank failure can trigger wider economic damage — a concept known as systemic risk.

Services Banks Typically Offer

For individuals:

• Savings and current accounts
• Debit and credit cards
• Personal loans and mortgages
• Online and mobile banking
• Foreign exchange services

For businesses:

• Business accounts and overdrafts
• Trade finance and letters of credit
• Payroll processing
• Merchant payment services
• Investment and treasury products

Bank vs. Credit Union vs. Fintech

A fintech provider may offer a slick app, but your money is usually held at a licensed bank behind the scenes. That distinction matters when things go wrong.

How to Check If a Bank Is Legitimate

If you are unsure whether an institution is properly licensed — especially in a market where fraudulent schemes exist — verify it directly:

1. Visit the central bank's website (for Nigeria: cbn.gov.ng).
2. Look for the list of licensed institutions or a "regulated entities" section.
3. Cross-check the institution's name against that list.
4. If it does not appear, treat it as unlicensed and avoid depositing money.

This step takes a few minutes and is the most reliable way to confirm a bank's status.