What are the different types of loans?

The first split that matters for any loan is secured vs. unsecured. A secured loan is backed by a specific asset — the lender can repossess or foreclose on that collateral if you stop paying, which generally lets secured loans carry lower interest rates and larger amounts than unsecured debt. An unsecured loan has no collateral backing it; the lender is relying entirely on your creditworthiness and promise to repay, which is why unsecured debt (personal loans, most credit cards) generally carries higher rates than secured debt of similar size.

By purpose

• Mortgage — secured by the property itself; the largest and longest-term consumer loan most people take on, typically repaid over 15-30 years, with fixed- and adjustable-rate structures available.
• Auto loan — secured by the vehicle; shorter terms than a mortgage, commonly repaid over 24-84 months, with the vehicle itself as collateral the lender can repossess on default.
• Student loan — federal student loans (backed and set by the U.S. Department of Education, with fixed rates set annually and built-in income-driven repayment/forgiveness options) are structurally different from private student loans (issued by banks or credit unions, underwritten on credit like other consumer loans, generally without federal repayment protections).
• Personal loan — typically unsecured, fixed-rate, fixed-term installment debt used for a wide range of purposes (debt consolidation, home improvement, major purchases) — approval and rate depend heavily on credit score and income, since there's no collateral to reduce the lender's risk.
• Business loan / line of credit — can be secured (backed by business assets, equipment, or a personal guarantee) or unsecured, and ranges from a term loan for a one-time need to a revolving line of credit for ongoing working-capital fluctuations.
• Revolving credit (credit cards, lines of credit) — unlike an installment loan with a fixed payoff schedule, revolving credit lets you borrow, repay, and re-borrow up to a limit; the Federal Reserve's consumer credit reporting treats revolving and non-revolving (installment) credit as the two fundamental categories of U.S. consumer debt.

What actually differs between these categories

• Collateral risk — miss payments on a secured loan and the lender can take the specific asset (foreclosure, repossession); miss payments on unsecured debt and the consequence is collections activity and credit damage, not loss of a specific asset (though a judgment could still lead to other collection remedies depending on your state).
• Typical rate spread — secured loans backed by real estate or a vehicle generally price lower than unsecured personal loans or credit cards, because the collateral reduces the lender's loss if you default.
• Term length — mortgages run the longest (15-30 years), followed by auto and student loans (typically under 10 years), with personal loans and revolving credit generally shorter or open-ended.
• Qualification standard — secured loans can sometimes be more attainable for borrowers with limited credit history, since the collateral reduces the lender's risk; unsecured loans lean more heavily on credit score and income alone.