A journal — sometimes called the book of original entry — is where every financial transaction is first recorded in chronological order. Each entry includes the date, accounts affected, amounts, and a brief description.
For example, if you buy office supplies for $500 in cash, the journal entry would debit "Office Supplies" ($500) and credit "Cash" ($500). This follows the double-entry system where every transaction has two sides.
After recording in the journal, entries are posted to the general ledger. The journal provides a complete, time-ordered trail of every transaction — essential for auditing and error tracking.