Answer
In double entry, a debit is an entry on the left of an account and a credit on the right. Debits increase assets, expenses, and drawings and decrease liabilities, income, and capital; credits do the opposite. Which to use depends on the account type and the effect of the transaction.
Assets/Expenses/Drawings: increase = Debit. Liabilities/Income/Capital: increase = Credit.Real-world example Receiving cash is a debit to cash (asset up); making a sale is a credit to sales (income up).