Created in 2009 by an unknown person with the alias Satoshi Nakamoto, the digital currency Bitcoin is traded online.
While predominately used for moving money or shopping on the internet, some venues, such as The Old Fitzroy pub in Sydney, Australia, allow people to pay with the currency digitally.
Considered the most well-known of a number of digital currencies, Bitcoin has seen increased interest in recent years in emerging markets such as East Africa. Kenyan start up BitPesa is using Bitcoin for international money transfers.
BitPesa's clients can pay suppliers from Nigeria, Uganda, Tanzania, Kenya and the Democratic Republic of Congo. The company launched a scheme in December which lets African companies pay Chinese suppliers in their local currency, a transaction which BitPesa settles through Bitcoin at the backend.
The currency is anchored in a so-called blockchain -- a way of digitally tracking the transactions to avoid the money being used more than once.
Its value fluctuates and is not regulated, although payment companies that trade with Bitcoin tend to fall under the same regulations as conventional money transfer services. Pictured: People attend a Bitcoin conference in New York in 2014.
BitPesa hopes its new China-Africa service will make it easier for African companies to work with Chinese suppliers and investors.