What is e-money?

Electronic money (also known as e-money, electronic cash, electronic currency, digital money, digital cash or digital currency) refers to money or scrip which is exchanged only electronically. Typically, this involves use of computer networks, the internet and digital stored value systems. Also, it is a collective term for financial cryptography and technologies enabling it.

An example of e-money is Chipknip, an electronic cash system used in the Netherlands.

Source: http://en.wikipedia.org/wiki/Electronic_cash