BEGINNER_DOC_001 // BEGINNERS / HOW-DOES-BITCOIN-WORK
HOW DOES
BITCOIN WORK?
BITCOIN WORK?
Bitcoin is digital money that anyone can send anywhere in the world without a bank,
government, or any middleman. It runs on a global network of computers that all agree on the same
record of who owns what — with no single point of control. This page explains the complete picture
from start to finish.
THE_BIG_PICTURE — END_TO_END_FLOW
① YOU — CREATE A WALLET
Generate a private key → derive a public key → derive an address
Your address is where others send bitcoin to you.
STEP 2
② YOU — CREATE A TRANSACTION
Spend a previous output → sign with your private key → set recipient address
Your signature proves you own the bitcoin you're spending.
STEP 3
③ NETWORK — BROADCAST & VALIDATE
Your wallet sends the transaction to nearby nodes
Nodes check: valid signature? sufficient funds? valid format?
Valid transactions enter the memory pool (mempool).
STEP 4
④ MINERS — CONFIRM IN A BLOCK
A miner selects transactions from the mempool
Solves a proof-of-work puzzle to produce a valid block
Broadcasts the block to the network — all nodes update their copy.
FINAL
⑤ BLOCKCHAIN — PERMANENT RECORD
The block is added to the blockchain — an immutable chain of all transactions
Recipient can now spend the bitcoin you sent them.
THE_FIVE_KEY_COMPONENTS
① Wallet
KEYS
A wallet doesn't store bitcoin — it stores your private keys. Your keys prove ownership of bitcoin recorded on the blockchain. Lose your keys, lose your bitcoin.
Private Key → Public Key → Address
(secret) (shareable) (shareable)
Anyone can send to your address. Only you (with your private key) can spend from it.
② Transaction
TRANSFER
A transaction is a signed message that moves bitcoin from one address to another. It references previous unspent outputs as inputs and creates new outputs locked to new addresses.
Input: I am spending output X from transaction Y
Output: Lock 0.5 BTC to address bc1q... (recipient)
Output: Lock 0.1 BTC to address 1A1z... (change back to you)
Fee: 0.0001 BTC (reward for the miner)
③ Network (Nodes)
P2P
Thousands of computers (nodes) around the world store the full blockchain and validate every transaction and block. There is no central server — every node is equal.
~20,000 reachable full nodes worldwide
Each node independently validates every rule
No single point of failure or control
④ Mining
PROOF OF WORK
Miners compete to solve a computationally expensive puzzle (proof-of-work). The winner adds the next block and earns the block reward plus transaction fees. This is what makes the blockchain tamper-proof.
Block reward (2024): 3.125 BTC per block
~1 block every 10 minutes
Rewriting history requires more work than the entire honest network
⑤ Blockchain
LEDGER
The blockchain is the shared record of every Bitcoin transaction ever made. Each block is cryptographically linked to the one before it — altering any block would invalidate every block after it.
Block 1 → Block 2 → Block 3 → ... → Block 840,000+
↑ Each block contains the hash of the previous block
↑ Changing history requires redoing all the work — impossible in practice
WHY_BITCOIN_EXISTS
THE PROBLEM IT SOLVES
Traditional money requires trusted third parties — banks, payment processors,
governments. They can freeze accounts, inflate the currency, or be hacked. Bitcoin removes
these intermediaries through cryptography and decentralization.
KEY PROPERTIES
Permissionless — anyone can participate, no account needed.
Censorship-resistant — no one can block your transaction.
Fixed supply — only 21 million BTC will ever exist.
Transparent — every transaction is publicly verifiable.
Censorship-resistant — no one can block your transaction.
Fixed supply — only 21 million BTC will ever exist.
Transparent — every transaction is publicly verifiable.
TERMINOLOGY_INDEX
Bitcoin (BTC)
The decentralized digital currency. Also the name of the network and protocol.
Satoshi
The smallest unit of Bitcoin. 1 BTC = 100,000,000 satoshis (sats).
Private Key
A secret number that proves ownership. Used to sign transactions. Never share it.
Address
A shareable destination for receiving bitcoin, derived from your public key.
Transaction
A signed instruction to move bitcoin from one address to another.
Node
A computer running Bitcoin software that validates and stores the blockchain.
Mining
The process of solving proof-of-work puzzles to add blocks to the blockchain.
Blockchain
The public ledger of every Bitcoin transaction, stored by all full nodes.
Peer-to-peer
A network where all participants connect directly — no central server.