Bitcoins are the unit of first peer to peer electronic currency

Bitcoins are the unit of first peer to peer electronic currency of the Bitcoin system. A commonly used shorthand for this is “BTC” to refer to a price or amount (eg: “100 BTC”). A Bitcoin isn't tangible. It is just a number associated with a Bitcoin Address. See also an easy intro to bitcoin.

However, if you don’t know what the whole ‘bitcoin’ thing is about, you may be confused.

“What Are Bitcoins?” is a common question that we get at FreeBitcoins.org – so we made up some useful pointers to help explain what it’s all about:

• Bitcoin is the world’s first peer to peer electronic currency! It’s like bittorrent, except totally legal.

• If you understand that Paypal = money, then you can apply the same thinking for bitcoins – it’s like paypal without all the huge fees and restrictions.

• If you understand how gold and silver = money, then think of bitcoins as the electronic version of gold & silver. There’s only a limited supply of them, and people trade them for items and money.

• No person or company is behind bitcoin, bitcoins are owned by the people who are connected to the bitcoin network (like you and me).

• When you send someone bitcoin, there’s no chargebacks. Bitcoin transactions are anonymous and private.

• Bitcoins are going up in value every day. People buy bitcoins like gold and silver. Owning bitcoins is highly recommended.

How can I get Bitcoins? 

There are a variety of ways to acquire Bitcoins:

• Accept Bitcoins as payment for goods or services.

• There are several services where you can trade them for traditional currency.

• Find a local trader on tradebitcoin (or somewhere else) and trade with him in cash.

• Create a new block (currently yields 50 Bitcoins).

• Participate in a mining pool.

What's the current total number of Bitcoins in existence? 

The number of blocks times the coin value of a block is the number of coins in existence. The coin value of a block is 50 BTC for each of the first 210,000 blocks, 25 BTC for the next 210,000 blocks, then 12.5 BTC, 6.25 BTC and so on. 

How divisible are Bitcoins? 

Technically, a Bitcoin can be divided down to 8 decimals using existing data structures, so 0.00000001 BTC is the smallest amount currently possible. Discussions about and ideas for ways to provide for even smaller quantities of Bitcoins may be created in the future if the need for them ever arises. 

What do I call the various denominations of Bitcoins? 

There is a lot of discussion about the naming of these fractions of Bitcoins. The leading candidates are:

• 1 BTC = 1 Bitcoin

• 0.01 BTC = 1 cBTC = 1 Centi-Bitcoin (also referred to as Bitcent)

• 0.001 BTC = 1 mBTC = 1 Milli-Bitcoin (also referred to as mbit (pronounced em-bit) or millibit)

• 0.000 001 BTC = 1 μBTC = 1 Micro-Bitcoin (also referred to as ubit (pronounced yu-bit) or microbit)

The above follows the accepted international SI units for thousandths, millionths and billionths. There are many arguments against the special case of 0.01 BTC since it is unlikely to represent anything meaningful as the Bitcoin economy grows (it certainly won't be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as "cent", "nickel", "dime", "pence", "pound", "kopek" and so on are to be discouraged. This is a worldwide currency.

One exception is the "satoshi" which is smallest denomination currently possible

• 0.000 000 01 BTC = 1 Satoshi (pronounced sa-toh-shee)

which is so named in honour of Satoshi Nakamoto the pseudonym of the inventor of Bitcoin.

For an overview of all defined units of Bitcoin (including less common and niche units), see Units.

Further discussion on this topic can be found on the forums here:

• We need names

• What to call 0.001 BTC