Credit scores are three-digit summaries of your borrowing history. They affect the rates you pay on loans, whether you're approved for a card, and sometimes even insurance pricing. While models differ, five ideas drive most scores. (1) Payment history: on-time payments are everything. A single late payment can stick for years, so set automatic payments for at least the minimum due. (2) Utilization: the percentage of your credit limits in use. Stay below 30%, and below 10% if you are preparing for a big loan. (3) Age of accounts: older is better. Keep your oldest accounts open if they're fee-free. (4) Mix of credit: having both installment loans (like auto) and revolving credit (cards) can help slightly. (5) New inquiries: opening many accounts at once can temporarily lower your score. Practical steps: pay on time, reduce balances before statement dates, and avoid unnecessary hard pulls. Use our credit utilization helper to estimate how payments this month will change your ratio next month. Over time, scores respond to steady habits, not tricks.