> For the complete documentation index, see [llms.txt](https://web3-encyclopedia.gitbook.io/web3-encyclopedia/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://web3-encyclopedia.gitbook.io/web3-encyclopedia/bitcoin/tl-dr.md).

# TL;DR 👀

<mark style="color:purple;">**What is Bitcoin**</mark>

<mark style="color:purple;">Bitcoin is the first-ever virtual currency designed to act as money and a form of payment outside the control of any one entity</mark>

<mark style="color:purple;">**Bitcoin's Blockchain Technology**</mark>

<mark style="color:purple;">A blockchain is a distributed ledger, a shared database that stores data. Data within the blockchain are secured by encryption methods</mark>

<mark style="color:purple;">**UTXO Model and Transaction Fees**</mark>

<mark style="color:purple;">An unspent transaction output (UTXO) is the technical term for the amount of digital currency that remains after a cryptocurrency transaction</mark>&#x20;

<mark style="color:purple;">The UTXO model is used in many cryptocurrencies because it allows users to track ownership of all portions of that cryptocurrency.</mark>

<mark style="color:purple;">Bitcoin uses UTXOs whereas Ethereum does not</mark>

<mark style="color:purple;">**Bitcoin Mining and Mempool**</mark>

<mark style="color:purple;">Bitcoin is a proof-of-work blockchain, and block validation takes an average of 10 minutes for the mining network to validate a block and create the reward</mark>

<mark style="color:purple;">The bitcoin reward is 6.25 BTC per block</mark>

<mark style="color:purple;">**What are Hard Forks and Soft Forks**</mark>

<mark style="color:purple;">A hard fork is a radical change to a network's protocol that makes previously invalid blocks and transactions valid, or vice-versa</mark>

<mark style="color:purple;">A soft fork is a change to the software protocol where only previously valid transaction blocks are made invalid</mark>

<mark style="color:purple;">Soft forks are backwards-compatible whereas hard forks are not</mark>

<mark style="color:purple;">**What is SegWit and the Lightning Network**</mark>

<mark style="color:purple;">Segregated witness (SegWit) is a protocol upgrade that protects against transaction malleability and decreases transaction times by increasing block capacity</mark>

<mark style="color:purple;">SegWit was a significant soft fork of the Bitcoin blockchain</mark>

<mark style="color:purple;">**Bitcoin Ecosystem**</mark>

<mark style="color:purple;">Bitcoin is used as a form of payment and as an investment vehicle around the world</mark>

<mark style="color:purple;">The Bitcoin network of miners make money from Bitcoin by successfully validating blocks and being rewarded</mark>

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<summary><mark style="color:yellow;">References</mark></summary>

[<mark style="color:purple;">https://www.investopedia.com/terms/b/bitcoin.asp</mark>](https://www.investopedia.com/terms/b/bitcoin.asp)

[<mark style="color:purple;">https://www.investopedia.com/terms/u/utxo.asp</mark>](https://www.investopedia.com/terms/u/utxo.asp)

[<mark style="color:purple;">https://www.investopedia.com/terms/h/hard-fork.asp</mark>](https://www.investopedia.com/terms/h/hard-fork.asp)

[<mark style="color:purple;">https://www.investopedia.com/terms/s/soft-fork.asp</mark>](https://www.investopedia.com/terms/s/soft-fork.asp)

[<mark style="color:purple;">https://ethereumclassic.org/knowledge/roadmap</mark>](https://ethereumclassic.org/knowledge/roadmap)

[<mark style="color:purple;">https://cointelegraph.com/blockchain-for-beginners/soft-fork-vs-hard-fork-differences-explained</mark>](https://cointelegraph.com/blockchain-for-beginners/soft-fork-vs-hard-fork-differences-explained)

[<mark style="color:purple;">https://www.investopedia.com/terms/s/segwit-segregated-witness.asp</mark>](https://www.investopedia.com/terms/s/segwit-segregated-witness.asp)

[<mark style="color:purple;">https://www.nasdaq.com/articles/a-look-at-the-game-theory-of-bitcoin-2021-09-13</mark>](https://www.nasdaq.com/articles/a-look-at-the-game-theory-of-bitcoin-2021-09-13)

[<mark style="color:purple;">https://dci.mit.edu/51-attacks</mark>](https://dci.mit.edu/51-attacks)

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