"There is nothing left now for us but to get ever deeper and deeper into debt to the banking system in order to provide the increasing amounts of money the nation requires for its expansion and growth. An honest money system is the only alternative." -- Frederick Soddy, M.A., F.R.S., Nobel Prize Winner, 1921
As the above makes clear, banks are able to manipulate "money" using various methods like the debiting of one account and the crediting of another, and so on, thus "balancing" the accounts. Banks also "create" money in more ways than one, through a trick that will be looked at later on.
Economists use the term "create" when observing the process by which money comes into being. Thus, creation means making something that did not exist before.
A sawmill makes boards, workers build houses from timber, a glass-blower makes fancy glass ornaments. In these examples, they did not "create", but converted already existing materials into a more usable, and thus more valuable form.
However, money "creation" is somewhat different. Here, and here alone, man "creates" something out of nothing. Pieces of worthless paper are printed, given various denominational values, which can be used to purchase, for example, a glass ornament. Its value (of the money, or piece of paper) has been "created" literally out of thin air.
As we can see from the above, manufacturing money is dirt cheap, and whoever does the "creating" and issuing stands to make impressive profits (Click below for full article)