what is bitcoin 
bitcoin btc is a cryptocurrency a virtual currency designed to act as money and a form of payment outside the control of any one person group or entity this removes the need for trusted third party involvement e g a mint or bank in financial transactions it is rewarded to blockchain miners who verify transactions and can be purchased on several exchanges bitcoin was introduced to the public in 2009 by an anonymous developer or group of developers using the name satoshi nakamoto it has since become the most well known and largest cryptocurrency in the world its popularity has inspired the development of many other cryptocurrencies read on to learn more about the cryptocurrency that started it all the history behind it how to mine it buy it and what it can be used for investopedia julie bangunderstanding bitcoinin august 2008 the domain name bitcoin org was registered it was created by satoshi nakamoto and martti malmi who worked with the anonymous nakamoto to develop bitcoin 1in october 2008 nakamoto announced to the cryptography mailing list at metzdowd com i ve been working on a new electronic cash system that s fully peer to peer with no trusted third party the now famous white paper published on bitcoin org entitled bitcoin a peer to peer electronic cash system would become the magna carta for how bitcoin operates today 23on jan 3 2009 the first bitcoin block was mined called block 0 it is also known as the genesis block and contains the text the times 03 jan 2009 chancellor on brink of second bailout for banks perhaps proof that the block was mined on or after that date 4bitcoin rewards are halved every 210 000 blocks for example the block reward was 50 new bitcoins in 2009 on may 11 2020 the third halving occurred bringing the reward for each block down to 6 25 bitcoins the fourth halving occurred in april 2024 and lowered the reward to 3 125 bitcoins the next halving should happen in mid 2028 and reduce the reward to 1 5625 btc one bitcoin is divisible to eight decimal places 100 millionths of one bitcoin and this smallest unit is referred to as a satoshi on jan 8 2009 the first version of the bitcoin software was announced to the cryptography mailing list and on jan 9 2009 block 1 was mined and bitcoin mining began 5bitcoin s blockchain technologybitcoin as a form of digital currency isn t hard to understand for example if you own a bitcoin you can use your cryptocurrency wallet to send smaller portions of that bitcoin as payment for goods or services by contrast the way bitcoin actually works is very complex a blockchain is a distributed ledger a shared database of information that is chained together via cryptographic techniques distributed means that it is stored on many computers rather than on a centralized server as is typical of data storage a network of automated programs installed on these computers maintains the blockchain and performs the functions necessary for it to operate a block on a blockchain is a file that contains a block header transaction counter and the transactions recorded in the block the transaction counter lists how many transactions are in the block while the block header is made up of several elements as noted each block contains the hashed information of the previous block this creates a chain of encrypted blocks files that contain information from all previous blocks going back to the first block of the blockchain bitcoin uses the sha 256 hashing algorithm to encrypt hash the data stored in the blocks on the blockchain simply put transaction data stored in a block is encrypted into a 256 bit 64 digit hexadecimal number that number contains all the transaction data and information linked to the blocks before that block while the data in a block is encrypted and used in the next block the block is not inaccessible or non readable the hash is used in the next block then its hash is used in the next and so on but all blocks can be read this makes it so blocks cannot be changed without changing all other blocks and ensures anyone can audit the blockchain 