When you're carrying more than one debt — a couple of credit cards, maybe a personal loan — and you have some extra money to put toward paying them down, the question becomes which one to target first. Two approaches show up most often in general personal-finance discussion, and they optimize for different things.

Smallest balance first

One approach is to put extra payments toward whichever balance is smallest, regardless of interest rate, while paying minimums on everything else. The logic is momentum: clearing a balance entirely, even a small one, produces a visible result quickly, and that result tends to make people more likely to keep going.

Highest interest rate first

The other approach targets whichever debt carries the highest interest rate first, regardless of balance size. The logic there is mathematical: interest is the actual cost of carrying debt, so paying down the most expensive balance first minimizes the total interest paid over time, even if it takes longer to see a balance hit zero.

Neither is universally "correct"

One tends to save more money over time; the other tends to be easier to stick with for some people. Which fits better depends on your balances, your rates, and honestly on which one you're more likely to follow through on — a technically optimal plan you abandon after two months accomplishes less than a slightly less optimal one you stick with.

This is general information, not personal advice. Your actual rates, balances, and situation matter a lot here — for anything beyond understanding the two approaches, a financial advisor can help you apply this to your numbers specifically.