In accounting, a debit is an entry made on the left side of a ledger account. Debits increase assets and expenses while decreasing liabilities, equity, and revenue.
For example, when you receive $5,000 in cash, you debit the Cash account (asset goes up). When you pay rent, you debit the Rent Expense account (expense goes up) and credit Cash (asset goes down).
Debits and credits are the two halves of the double-entry system. Every transaction must have equal debits and credits. The word "debit" comes from the Latin word debere meaning "to owe."