This chapter explains the rules regarding debits and credits. Debits and credit increase and decrease certain accounts. Spend some time learning the rules of debits and credits, since they are the foundation of accounting principles. Posting a debit where a credit should be, or vice versa, will cause you to be out of balance. You will then have to re-trace all of your postings to uncover your error, which would be very frustrating and time-consuming.