Bitcoin is a decentralized digital currency that allows peer-to-peer transactions on the internet without relying on a central bank or authority. It was created in 2008 by an anonymous person or group under the pseudonym Satoshi Nakamoto and began use in 2009. Bitcoin transactions are recorded on a public distributed ledger called the blockchain, which is maintained collectively by a global network of computers (nodes). This ensures transparency, security, and immutability of transaction records. Key characteristics of Bitcoin include:

• It enables secure, direct digital money transfers between people anywhere in the world.
• It is decentralized—no single company, country, or institution controls it.
• The total supply of Bitcoin is capped at 21 million coins, making it immune to inflation.
• Bitcoin can serve as an investment, a store of value similar to gold, a medium of exchange, or a way to transfer value globally.
• Unlike traditional fiat currencies, Bitcoin is not backed by any government and operates on open-source software with a transparent monetary policy.
• Bitcoin transactions are validated through a process called mining, which involves solving cryptographic puzzles and requires significant computational power.

Bitcoin is widely recognized as the first and largest cryptocurrency by market capitalization, often referred to as digital gold, and is legal to use, hold, and trade in many parts of the world. It allows for fast, low-cost transactions and gives individuals maximum control over their digital assets without intermediaries such as banks or payment processors. In essence, Bitcoin is a form of digital money native to the internet that offers an alternative to traditional financial systems with features of decentralization, transparency, and scarcity. It has inspired the creation of thousands of other cryptocurrencies since its inception. This summary integrates key points from multiple authoritative sources explaining what Bitcoin is and how it works.