The Rules of Debits and Credits
Debits increase asset and expense accounts, and decrease liability, equity, and revenue accounts. Credits do the opposite. Every journal entry must have equal total debits and credits.
T-Account Visualization
Think of each account as a T-shape. The left side is always the debit side, the right side is always the credit side. For asset accounts, increases go on the left (debit). For liability and equity accounts, increases go on the right (credit).
Remember: DEALER - Debits increase Expenses, Assets, and Losses. Credits increase Equity, Assets (contra), Liabilities, and Revenue.