To handle their daily transactions, to collect information, to prepare and design individual companies, both private households, companies and the state need money which is available in a so-called transaction fund.
It is important to be liquid to a certain extent in order to be able to meet expected and unexpected payment obligations.
The more the economic performance increases, the more the costs of the transactions and the demand for a transaction register increase. This is essentially determined by the level of income.
English 
German 