Closing transfers temporary account balances into permanent equity. Revenue and expense accounts measure one period, so they start the next period at zero. Owner draws or corporate dividends also close to equity, but they are not included in net income. Assets, liabilities and permanent capital balances remain open.
A traditional sequence closes revenue to Income Summary, closes expenses to Income Summary, transfers the resulting profit or loss to capital or retained earnings, then closes drawings. Some software presents the year roll automatically rather than posting visible close journals. The close-the-books date is a separate protection against backdated edits. A post-closing trial balance should contain permanent accounts only, with equal debit and credit totals.