Bitcoin (BTC) is a decentralized cryptocurrency that was first described in a 2008 whitepaper by an individual or group of individuals using the alias Satoshi Nakamoto. Officially launched in January 2009, Bitcoin is a peer-to-peer online currency that allows transactions to happen directly between equal and independent network participants without the need for any intermediary. Bitcoin is digital money that cannot be inflated or manipulated by any individual, company, government, or central bank. Bitcoin is recognized as one of the initial cryptocurrencies to come into use and has inspired the development of thousands of competing projects. There will only ever be 21 million BTC. Bitcoin is highly divisible, with its smallest unit, i.e. 0.000 000 01 BTC, called a "satoshi" or "sat." As bitcoin's value has risen, its easy divisibility has become a key attribute.

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, meaning that no company, country, or third party is in control of it, and anyone can become part of that network. The process by which new bitcoins are entered into circulation involves solving computationally difficult puzzles to discover a new block, which is added to the blockchain. The individuals who present their solution to the puzzle first are compensated with a certain number of bitcoins. Finally, 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).

One of Bitcoin's advantages comes from the fact that it was one of the initial cryptocurrencies to appear on the market. It has managed to create a global community and give birth to a new industry of millions of enthusiasts who create and use Bitcoin and other cryptocurrencies in their everyday lives. Bitcoin is often referred to as digital gold due to its potential for long-term utility. It is also used as a decentralized medium of exchange, providing for ownership rights as a physical asset or as a unit of account.

Bitcoin was launched in January 2009 by an individual or group of individuals using the alias Satoshi Nakamoto. The paper introducing Bitcoin wasn't the first idea for digital money drawing on the fields of cryptography and computer science—in fact, the paper referred to earlier concepts—but it was a uniquely elegant solution to the problem of establishing trust between different online entities, where people may be hidden (like bitcoin's own creator) by pseudonyms, or physically located on the other side of the planet. The first block on the Bitcoin network, known as the genesis block, was mined by Nakamoto, but the first known Bitcoin transaction occurred on May 22, 2010, when programmer Laszlo Hanyecz traded 10,000 Bitcoins for two pizzas. This event is now known as "Bitcoin Pizza Day." Over the years, many people have contributed to improving the cryptocurrency's software by patching vulnerabilities and adding new features. The fact that Bitcoin is not controlled by a single person or organization is core to its value proposition, and Satoshi's identity has never been revealed (and likely never will be).

You can create an account on Coinbase or an increasing number of other reputable financial technology companies to buy, send, and receive Bitcoin. Bitcoin is also increasingly accessible via traditional financial portfolios; for example, in October 2021, the first Bitcoin futures-based ETF was approved, and in January 2024, the first spot Bitcoin ETFs were approved. (ETFs are a popular way for investors to gain exposure to an asset like gold or tech stocks, and now Bitcoin.)

Bitcoin is often considered to be a "store of value," the same as gold is. New bitcoins are created by "mining" (up to a maximum of 21 million coins). Bitcoin mining is the process by which thousands of computers worldwide compete to record and verify transactions on the network. These specialized computers, known as 'mining rigs,' perform the equations required to verify and record a new transaction. In the early days, a typical desktop PC was powerful enough to participate, allowing pretty much anyone curious to try their hand at mining. These days, however, the computers required are massive, specialized, and often owned by businesses or large numbers of individuals pooling their resources. As of October 2021, Cambridge University researchers estimate that U.S.-based miners maintain the highest percentage of global mining by country.

Bitcoin halving, also referred to as "the halvening," is a scheduled event in Bitcoin's timeline that takes place approximately every four years or after 210,000 blocks have been mined. During this event, the quantity of new bitcoins entering circulation every 10 minutes, known as block rewards, is decreased by half. For example, in May 2020, the block rewards were reduced from 12.5 to 6.25 bitcoins. This process seeks to manage Bitcoin's inflation rate and restrict the total supply of bitcoins to 21 million. The halving mechanism is structured to lessen the number of new coins entering the Bitcoin network, thereby influencing the supply dynamics of Bitcoin. However, the influence of halving on Bitcoin's supply dynamics is multifaceted and continues to be explored. The next Bitcoin halving is scheduled to occur in 2024, subject to the mining of the requisite number of blocks.

Bitcoin is a decentralized digital currency, which means it's not owned by any individual, company, or government. It was created by an individual or group of individuals using the pseudonym "Satoshi Nakamoto". However, the true identity of Satoshi Nakamoto remains unknown. Bitcoin operates on a technology called blockchain, a public ledger containing all transaction data from anyone who uses bitcoin. Transactions are added to "blocks" or the links of code that make up the chain, and each transaction must be recorded on a block. But despite its creator, no one person, entity or organization has control over the network. Bitcoin aims to be maintained by a community of volunteer coders and strives to be run by an open network of dedicated computers spread around the world. This community intends to work together to ensure the integrity and smooth operation of the Bitcoin network.

The value of Bitcoin is determined by several factors, primarily supply and demand. Bitcoin's supply is finite, with only 21 million bitcoins ever to be produced. This scarcity is a key factor in its value. The rate at which new bitcoins are created is designed to slow down over time, which may influence demand. Demand for Bitcoin can be influenced by various factors, including its utility as a medium of exchange and its acceptance by businesses and consumers. Its potential utility in the digital economy is another factor. Factors such as the cost of producing a bitcoin through the mining process, the number of competing digital currencies, regulations governing its sale and use, and media coverage can all impact its price. It's important to note that Bitcoin's price may experience fluctuations in value due to these and other market factors.

Bitcoin can be utilized in a variety of ways, akin to traditional currencies. Bitcoin may be utilized for transactions with merchants that accept Bitcoin and other cryptocurrencies. Some businesses provide a Bitcoin payment alternative for their products and services, both online and offline. For example, Bitcoin can be used to acquire gift cards for preferred brands, cover travel and everyday expenses, or even facilitate bill payments. Bitcoin may also be utilized via Bitcoin debit cards, which operate in a manner similar to traditional debit cards, enabling you to utilize Bitcoin in a manner similar to traditional currencies. Bitcoin can also be utilized through remittance services, Bitcoin ATMs, and peer-to-peer (P2P) marketplaces. It's crucial to note that the availability of these options may vary depending on your location and the specific service provider. It is crucial to be aware of the terms and conditions of the service when utilizing Bitcoin for transactions.

Altcoins, short for "alternative coins," are all cryptocurrencies other than Bitcoin. They emerged in the crypto market with the aim to address Bitcoin's perceived limitations and introduce additional or new capabilities. For instance, some altcoins use different consensus mechanisms to validate transactions or open new blocks. Altcoins are typically designed and released by developers with different visions or uses for their tokens or cryptocurrency. Examples of altcoins include Ethereum, Litecoin, and Ripple, among others. While Bitcoin is primarily a digital currency, many altcoins serve various functions, such as Ethereum's Ether, which is used to pay transaction fees within its network. Some altcoins, like Litecoin, have different transaction validation processes that aim to be efficient and mindful of energy consumption. Therefore, while Bitcoin maintains a presence in the cryptocurrency space, altcoins contribute to the diversity and innovation in the market, each with its unique features and uses.

Bitcoin transactions are frequently seen as anonymous due to the decentralized nature of blockchain technology. However, this is not entirely accurate. While Bitcoin transactions do not directly reveal personal information, they are not entirely anonymous but rather pseudonymous. Each transaction is linked to a public key, an alpha-numerical string that serves as a pseudonym for the user. This public key, while not directly linked to the user's real-world identity, can be traced using tools known as Bitcoin explorers. These tools can track activity on the blockchain, including the amount sent and the addresses involved in a transaction. However, linking a public key to a real-world identity is not straightforward, providing users with a degree of pseudo-anonymity. It's important to note that this pseudo-anonymity can be compromised when users exchange their cryptocurrency for other digital assets, or when they register with centralized digital asset platforms or blockchain-based applications, as these platforms may implement a Know Your Customer (KYC) process.

As of December 18, 2023, there were 19,573,975 bitcoins in existence. Bitcoin was designed with a cap to limit its supply to 21 million coins. This cap was implemented by Bitcoin's anonymous creator(s), known as Satoshi Nakamoto, to manage its availability over time, which may influence its demand. The process of adding new bitcoins to the supply occurs approximately every 10 minutes, which is the average time it takes to create a new block on the Bitcoin blockchain. However, the number of bitcoins created per block is halved after every 210,000 blocks, or about once every four years. This systematic reduction means that the total number of bitcoins issued will likely never reach the full 21 million due to the use of rounding operators in the Bitcoin codebase. It is projected that the final bitcoin (or more accurately, the final satoshi, as 1 bitcoin equals 100 million satoshis) may not be generated until around 2140.