Book: all records of one business.

Account: one labeled bucket: bank, customer, rent, machine.

Ledger: diary of all lines, oldest first.

Double entry: each move written twice, debit + credit = zero.

Debit / Credit: left / right side. Assets and costs grow with debit. Debts, equity, sales grow with credit.

Accrual: record when deal happens, not when cash moves.

Receivables: customers owe you. Payables: you owe vendors.

Unearned revenue: paid for work not yet done. You owe the job.

Prepayment: paid for months not yet used. They owe you time.

Fixed asset: big item you keep. Slowly becomes cost via depreciation. Total so far = accumulated depreciation.

Inventory: stock to sell. Asset until sold.

Drawings / Contributions: owner out / in. Never profit.

Main bank: your real cash account; recorded money moves here. The unexplained month-end change posts to Misc.

Income statement: sales minus costs in a period. The film.

Balance sheet: own minus owe at a date. The photo. Rest = net worth.

Trial balance: all balances at once. Debits = credits.

Locked profit: growth in worth this period, without owner money. Proven by balances.