In small businesses that don’t have computers, these records still exist in paper form.
In computerised systems, the same information needs to be recorded – but in electronic form.
Ledgers still exist (nominal, receivables, payables) though they will be computer records rather than separate paper books.
Journals are still needed eg to carry out and explain why a debt has been written off. Hopefully, someone will authorise a printout of the adjustment.
The cash book will not be a separate paper book but the cash account is still often referred to as the ‘cash book’ even though it is a computer record.