Bitcoin (₿) is a decentralized digital currency that can be transferred on the peer-to-peer bitcoin network. Bitcoin transactions are verified by network nodes through cryptography and recorded in a public distributed ledger called a blockchain. The cryptocurrency was invented in 2008 by an unknown person or group of people using the name Satoshi Nakamoto. The currency began use in 2009when its implementation was released as open-source software.
What is Bitcoin?
Bitcoin is the first and most widely recognized cryptocurrency. It enables peer-to-peer exchange of value in the digital realm through the use of a decentralized protocol, cryptography, and a mechanism to achieve global consensus on the state of a periodically updated public transaction ledger called a ‘blockchain.’
Data structure of blocks in the ledger.
Number of bitcoin transactions per month, semilogarithmic plot
Number of unspent transaction outputs
The bitcoin blockchain is a public ledger that records bitcoin transactions. It is implemented as a chain of blocks, each block containing a cryptographic hash of the previous block up to the genesis block[c] in the chain. A network of communicating nodes running bitcoin software maintains the blockchain.: 215–219 Transactions of the form payer X sends Y bitcoins to payee Z are broadcast to this network using readily available software applications.
Network nodes can validate transactions, add them to their copy of the ledger, and then broadcast these ledger additions to other nodes. To achieve independent verification of the chain of ownership each network node stores its own copy of the blockchain. At varying intervals of time averaging to every 10 minutes, a new group of accepted transactions, called a block, is created, added to the blockchain, and quickly published to all nodes, without requiring central oversight. This allows bitcoin software to determine when a particular bitcoin was spent, which is needed to prevent double-spending. A conventional ledger records the transfers of actual bills or promissory notes that exist apart from it, but the blockchain is the only place that bitcoins can be said to exist in the form of unspent outputs of transactions.
What is Bitcoin used for?
At its most basic level, Bitcoin is useful for transacting value outside of the traditional financial system. People use Bitcoin to, for example, make international payments that are settled faster, more securely, and at lower transactional fees than through legacy settlement methods such as the SWIFT or ACH networks.
In the early years, when network adoption was sparse, Bitcoin could be used to settle even small-value transactions, and do so competitively with payment networks like Visa and Mastercard (which, in fact, settle transactions long after point of sale). However, as Bitcoin became more widely used, scaling issues made it less competitive as a medium of exchange for small-value items. In short, it became prohibitively expensive to settle small-value transactions due to limited throughput on the ledger and the lack of availability of second-layer solutions. This supported the narrative that Bitcoin’s primary value is less as a payment network and more as an alternative to gold, or ‘digital gold.’ Here, the argument is that Bitcoin derives value from a combination of the technological breakthroughs it integrates, its capped supply with ‘built-into-the-code’ monetary policy, and its powerful network effects. In this regard, the investment thesis is that Bitcoin could replace gold and potentially become a form of ‘pristine collateral’ for the global economy.
Another popular narrative is that Bitcoin supports economic freedom. It is said to do this by providing, on an opt-in basis, an alternative form of money that integrates strong protection against monetary confiscation, censorship, and devaluation through uncapped inflation. Note that this narrative is not mutually exclusive from the ‘digital gold’ narrative.
How does Bitcoin work?
Bitcoin was created by Satoshi Nakamoto, a pseudonymous person or team who outlined the technology in a 2008 white paper. It’s a simple concept: bitcoin is digital money that allows for secure peer-to-peer transactions on the Internet.
The invention of Bitcoin was a breakthrough in cryptography. Bitcoin’s key innovation was the blockchain — a piece of software that acts like a ledger, logging every transaction ever made using bitcoin. Unlike a bank’s ledger, the Bitcoin blockchain is distributed and verified across a network of computers. No company, country, or third party is in control of it. And anyone can become part of that network.
Bitcoin is based on encryption, making it extremely secure and universally accessible. Creating a “bank account” on the global Bitcoin network generates an extremely long password a.k.a. a “private key” that is impossible for anyone else to guess. Anyone, anywhere with Internet access can receive, send, and hold Bitcoin using the public version of their key (i.e. the version of their private key that can be freely shared in order to securely receive funds).
There will only ever be 21 million BTC. Bitcoin is digital money that cannot be inflated or manipulated by any individual, company, government, or central bank.
Bitcoin is highly divisible. You can hold, send, or receive fractions of a BTC. The smallest unit, i.e. 0.000 000 01 BTC, is called a “satoshi” or “sat.” As bitcoin’s value has risen, its easy divisibility has become a key attribute.