In other words, it's an accounting journal in place of both of those two journals. A business can thus either have a CRJ AND a CPJ or they can just have a cash book.
The cash book therefore contains all entries of cash received and all entries of cash paid out. It would contain columns showing the date, the amounts and a description of the transaction. It is often shown with a left side and right side. All receipts go on the left side (debit side of cash/bank) and all payments on the right side (credit side of cash/bank).
A business can keep a manual (hard copy) cash book - an actual book - or it can use accounting software that would include a digital version of this in the program itself.