An accounting journal is a detailed account of all the financial transactions of a business.Before computerized bookkeeping and accounting, the transactions were entered manually into a journal and then posted to the general ledger.A Journal Entry is simply a summary of the debits and credits of the transaction entry to the Journal. Journal entries are important because they allow us to sort our transactions into manageable data. Every time a transaction occurs, it's recorded using a journal entry.Every transaction has two journal entries: a debit and a credit. Debits must always equal credits. Because debits equal credits, double-entry accounting prevents some common bookkeeping errors.Now, it's common for a bookkeeper to keep seven different accounting journals , with each journal covering a different aspect of the business. Each of the journals follow the general debit and credit format, but with categories relating to that specific aspect of the business.