Depends on a lot of factors. If you have high interest debt (like credit card debt), I'd pay that off.

Then, if you don't have an emergency savings fund of at least a couple of months of expenses, I'd put money into a high yield savings account.

Then I'd look at paying off other debt like student loans or a car loan. If the interest rate is low, like 3% or less, I wouldn't pay it off but if it's say 6% or 8% I would.

Then I'd look at investing in the business if you expect a good return on your investment. This might actually come before paying down the more moderate interest rate loans depending on how much of a return you expect on the investment. Like if you expect a 10% return on the investment in your business, then make the investment rather than paying down a 6% interest rate loan.

Say you come into a chunk of money, around $20k, how do you use it?