Imagine, if you can, that you are a German pensioner who has retired to the golden shores of Australia. Every month, the German government will send you your pension, which you can withdraw from a local bank in Australia. It probably does not cross your mind how this process actually happens. But until very recently, it was a process that was done manually the Bundesbank created a magnetic file and then couriered it on a plane down to Australia, where the relevant bank processed the information and made the payments.
Unless you are the courier, this system was clearly not ideal. The wrong files could be sent, the files could be...