Good debt is money you’ve borrowed that improves your financial position by increasing in value. Two examples are mortgage and business loans. Mortgage loans pay for houses that hopefully increase in value, have tax advantages, or can be rented out for positive cash flow. Business loans finance business operations that help you make more money. Good debt is when you take in more money than you are paying out for the loan. You have to be careful because good debt can easily become bad debt. Purchasing a home for more than you can reasonably afford is an example.
Bad debt is used to purchase items that depreciate in value or does not improve your financial position. A lot of debt falls under this category. Credit card debt is a good example especially if you do not pay off the balance in full each month.
Your credit report (FICO score) does not really differentiate between good and bad debt but examines the total amount owed and your payment history. For this reason, you do not want to have too much debt, either good or bad but it is important to realize that if you are going to have debt, have good debt.