Every event the books capture is written as a journal entry — at least one account debited, at least one credited, totals equal. Software creates most entries invisibly when you issue invoices or match bank feeds; manual journal entries handle the rest, such as corrections and adjustments.
Entries post from the journal into the general ledger, which is why any ledger balance can be decomposed back into the entries — and the documents — that built it.
Why It Matters
Journal entries are the atoms of an audit trail. When something looks wrong in a report, the fix is found by reading entries; when an accountant "adjusts" your books at year-end, adjusting journal entries are literally what they write. Knowing the shape of an entry lets you read your own books instead of taking them on faith.
Example
Issue a $1,000 invoice: debit Accounts Receivable $1,000, credit Design Revenue $1,000. Collect it: debit Cash $1,000, credit Accounts Receivable $1,000. Two entries, four lines — the entire life of an invoice in the books.
Frequently Asked Questions
Does invoicing create a journal entry automatically?
In accounting software, yes — issuing an invoice posts the receivable/revenue entry for you. A standalone invoice document does not; the entry happens wherever your books are kept.