A Monthly Manual process is one performed by a person once per month, such as invoicing customers out of QuickBooks Online.
The term names two properties of a process at once: how often it runs, and whether a person has to run it. On a spectrum, the opposite of Monthly Manual is 📝Automated Transactional processing, in which every cash entry is automatically matched to its accrual accounting entry as soon as it is entered into the books. A given process can be placed along that spectrum, from a person's monthly task to an automated step that happens with each transaction.
The cost of a monthly cadence for the books as a whole is the subject of 📝The Monthly Close is a Bad Habit.