buying and selling bitcoins for ZAR

Bitcoin is a digital and global money system currency. ... Money can be exchanged without being linked to a real identity. The mathematical field of cryptography is the basis for Bitcoin's security.

A pseudonymous software developer going by the name of Satoshi Nakamoto proposed bitcoin in 2008, as an electronic payment system based on mathematical proof. The idea was to produce a means of exchange, independent of any central authority, that could be transferred electronically in a secure, verifiable and immutable way.

To this day, no-one knows who Satoshi Nakamoto really is.

In what ways is it different from traditional currencies?

Bitcoin can be used to pay for things electronically, if both parties are willing. In that sense, it's like conventional dollars, euros, pounds, or even South African Rand , which are also traded digitally.

But it differs from fiat digital currencies in several important ways:

Bitcoin is a cryptocurrency that is conducted on a public ledger, the "blockchain." Digitally transferred, it exists only online. Much like gold, it can have monetary value while also being a commodity, but it’s still its own currency. It is also decentralized and not managed by a single entity, but rather a group of people who process transactions, called miners. This means it is not subject to government regulations when traded or spent, and you don't need a bank to use it.

As a new user, you can get started with Bitcoin without understanding the technical details. Once you've installed a Bitcoin wallet on your computer or mobile phone, it will generate your first Bitcoin address and you can create more whenever you need one. You can disclose your addresses to your friends so that they can pay you or vice versa. In fact, this is pretty similar to how email works, except that Bitcoin addresses should be used only once.

Miners are in charge of making sure bitcoin transactions made by users are recorded and legit. Simply put, they do this by grouping every new bitcoin transaction made during a set time frame into a block. Once a block is made, it is added to the chain, which is linked together with a complex cryptography. This chain of blocks is the public ledger, and its extreme complexity is what currently protects transactions.

With bitcoin, on the other hand, the supply is tightly controlled by the underlying algorithm. A small number of new bitcoins trickle out every hour, and will continue to do so at a diminishing rate until a maximum of 21 million has been reached. This makes bitcoin more attractive as an asset – in theory, if demand grows and the supply remains the same, the value will increase. 

Bitcoin transactions cannot be reversed, unlike electronic fiat transactions.

This is because there is no central "adjudicator" that can say "ok, return the money." If a transaction is recorded on the network, and if more than an hour has passed, it is impossible to modify.

While this may disquiet some, it does mean that any transaction on the bitcoin network cannot be tampered with.

The smallest unit of a bitcoin is called a satoshi. It is one hundred millionth of a bitcoin (0.00000001) – at today's prices, about one hundredth of a cent. This could conceivably enable microtransactions that traditional electronic money cannot.