Everything Bitcoin, in plain words, with sources

Bitcoin is digital money that no company or government runs. Anyone can send it to anyone over the internet, and no one can create more than 21 million coins. The network started on 3 January 2009.

Satoshi Nakamoto: Creator of Bitcoin (pseudonym), active 2008–2011. Wrote the Bitcoin whitepaper (31 Oct 2008), mined the genesis block and released Bitcoin v0.1 (8 Jan 2009). Handed the project to other developers in December 2010 and stopped writing in April 2011. First known message: email to Adam Back, 20 Aug 2008.

Every 210,000 blocks, roughly every four years, the number of new bitcoins paid to miners per block is cut in half. This is how Bitcoin's supply is capped at 21 million.

Lightning is a payment network built on top of Bitcoin. Two parties lock bitcoin in a shared channel and then pay each other instantly and cheaply off-chain; payments can hop across channels to reach anyone.

Taproot is a 2021 upgrade that added Schnorr signatures and a way to hide unused spending conditions. Complex wallets, such as multisig, can look like ordinary single-key payments.

Stratum V2 is the newer protocol between miners and pools. It encrypts the connection, uses compact binary messages and, optionally, lets the miner rather than the pool choose which transactions go into a block.

Strategy, formerly MicroStrategy, is a US software company that turned itself into the largest corporate holder of bitcoin. It has been buying since August 2020, funded mostly by selling shares and bonds.

Metaplanet is a Tokyo-listed Japanese company that keeps its reserves in bitcoin, often called “Asia's Strategy”. Its goal is to own 210,000 BTC, 1% of all bitcoin, by the end of 2027.

A spot bitcoin ETF is a fund traded on a stock exchange that holds real bitcoin. It lets people get bitcoin price exposure through an ordinary brokerage account, without holding keys themselves.

On 22 May 2010 Laszlo Hanyecz paid 10,000 BTC for two pizzas, the first well-known purchase of real goods with bitcoin. 22 May is now celebrated as Bitcoin Pizza Day.

During a crash, a BitcoinTalk user admitted he was a bad trader, a little drunk, and simply holding. He misspelled “holding” in the title.

Michael Saylor is the co-founder and executive chairman of Strategy (formerly MicroStrategy), the company that holds more bitcoin than any other. Since 2020 he has been bitcoin's loudest corporate advocate, known for his quotes and memes.