# Learn Bitcoin

Canonical page: https://mybitcoinexplorer.com/learn

- [What is Bitcoin?](https://mybitcoinexplorer.com/learn/what-is-bitcoin/markdown): Bitcoin is digital money with no bank in charge. Learn how it works, who keeps the record, and why people use it, in plain English with diagrams.
- [How does Bitcoin work?](https://mybitcoinexplorer.com/learn/how-does-bitcoin-work/markdown): How a Bitcoin payment goes from your wallet to the blockchain: signing, checking, waiting in the mempool, mining and confirmation, step by step.
- [Who created Bitcoin?](https://mybitcoinexplorer.com/learn/who-created-bitcoin/markdown): Bitcoin was launched in 2009 by Satoshi Nakamoto, a pseudonym that has never been linked to a proven identity. Here is what is actually known.
- [The Bitcoin whitepaper, explained](https://mybitcoinexplorer.com/learn/bitcoin-whitepaper/markdown): A section-by-section, plain-English guide to the 9-page paper that started Bitcoin: transactions, timestamps, proof of work, incentives and privacy.
- [Satoshis and Bitcoin units](https://mybitcoinexplorer.com/learn/satoshis-and-bitcoin-units/markdown): 1 bitcoin = 100,000,000 satoshis. Learn the units BTC, mBTC, bits and sats, convert between them exactly, and see why software counts in sats.
- [Why there will only be 21 million bitcoin](https://mybitcoinexplorer.com/learn/bitcoin-supply-21-million/markdown): New bitcoin is issued on a fixed schedule that halves every 210,000 blocks. See the maths behind the 21 million cap and who enforces it.
- [What does decentralized mean in Bitcoin?](https://mybitcoinexplorer.com/learn/decentralization/markdown): Decentralized means no person, company or government runs Bitcoin. See how power is split between nodes, miners, developers and users.
- [The double-spending problem](https://mybitcoinexplorer.com/learn/double-spending-problem/markdown): Digital money is easy to copy. Learn how Bitcoin stops anyone spending the same coins twice, without a bank, using UTXOs, blocks and proof of work.
- [Is Bitcoin anonymous?](https://mybitcoinexplorer.com/learn/is-bitcoin-anonymous/markdown): Bitcoin is pseudonymous, not anonymous. Every payment is public forever, and names stay hidden only until something links them to you. Learn how.
- [How is Bitcoin different from bank money?](https://mybitcoinexplorer.com/learn/bitcoin-vs-bank-money/markdown): A bank balance is a promise from your bank; self-custodied bitcoin is controlled directly by your keys. Compare freezing, supply, fees and reversals.
- [Where does new bitcoin come from?](https://mybitcoinexplorer.com/learn/where-does-new-bitcoin-come-from/markdown): Every new bitcoin is created by miners in the first transaction of each block, on a fixed schedule every node checks. See how much and how often.
- [What is a Bitcoin transaction?](https://mybitcoinexplorer.com/learn/what-is-a-bitcoin-transaction/markdown): A Bitcoin transaction spends existing coins (inputs) and locks new ones to their next owners (outputs). See how it works with a real example.
- [UTXOs: how Bitcoin balances really work](https://mybitcoinexplorer.com/learn/understanding-utxos/markdown): Bitcoin has no account balances. Your balance is the total of unspent transaction outputs (UTXOs) your keys can unlock. Learn how UTXOs work.
- [Transaction inputs](https://mybitcoinexplorer.com/learn/transaction-inputs/markdown): An input points to an earlier output by txid and index, and supplies the signature that unlocks it. Learn what an input contains and why it has no amount.
- [Transaction outputs](https://mybitcoinexplorer.com/learn/transaction-outputs/markdown): Every output is an amount in sats plus a locking script that says who can spend it next. Learn how outputs, addresses and output numbers fit together.
- [Change outputs](https://mybitcoinexplorer.com/learn/change-outputs/markdown): When you spend a coin worth more than the payment, the rest returns to you as a change output. Learn why change exists and why it can matter for privacy.
- [How Bitcoin transaction fees work](https://mybitcoinexplorer.com/learn/bitcoin-transaction-fees/markdown): Bitcoin fees are inputs minus outputs, priced by size in sat/vB, not by amount sent. Learn what sets fees, how to pay less and how to fix a stuck payment.
- [Fee rate: sats per vbyte](https://mybitcoinexplorer.com/learn/fee-rate-sat-per-vbyte/markdown): Fee rate is the fee divided by virtual size, in sats per vbyte (sat/vB). It is the number miners sort by. Learn how to calculate and choose one.
- [Transaction size, weight and vbytes](https://mybitcoinexplorer.com/learn/transaction-size-and-weight/markdown): Since SegWit, transactions are measured in weight units and vbytes, with witness data discounted. Learn how size is counted and why it sets your fee.
- [Transaction IDs (txid)](https://mybitcoinexplorer.com/learn/transaction-id-txid/markdown): A txid is the double SHA-256 hash of a transaction, shown in reverse byte order. Learn how it is made, where to find it and how to look one up.
- [What is a Bitcoin confirmation?](https://mybitcoinexplorer.com/learn/bitcoin-confirmations/markdown): A confirmation means your transaction is in a block, and each new block adds another. Learn how many you need, how long they take and why they matter.
- [Replace-by-fee (RBF)](https://mybitcoinexplorer.com/learn/replace-by-fee-rbf/markdown): Replace-by-fee lets you resend an unconfirmed Bitcoin transaction with a higher fee so it confirms faster. Learn the rules and how wallets do it.
- [Child pays for parent (CPFP)](https://mybitcoinexplorer.com/learn/child-pays-for-parent-cpfp/markdown): CPFP speeds up a stuck Bitcoin transaction by spending its output in a new high-fee child. Miners take both together. Learn when and how to use it.
- [The coinbase transaction](https://mybitcoinexplorer.com/learn/coinbase-transaction/markdown): The first transaction in every block, created by the miner, pays out the new-coin subsidy plus all fees. Learn its special rules and famous messages.
- [Locktime and sequence](https://mybitcoinexplorer.com/learn/locktime-and-sequence/markdown): Locktime stops a transaction confirming before a set block or time; sequence numbers enable RBF and relative timelocks. Learn how both work.
- [Dust and UTXO consolidation](https://mybitcoinexplorer.com/learn/dust-and-consolidation/markdown): Dust is an output worth less than it costs to spend. Learn the dust limit, when to consolidate small UTXOs to save fees, and the privacy trade-off.
- [Transaction batching](https://mybitcoinexplorer.com/learn/transaction-batching/markdown): Batching pays many recipients in one Bitcoin transaction, sharing fixed costs and saving block space. See how much it saves and who uses it.
- [Anatomy of a raw transaction](https://mybitcoinexplorer.com/learn/anatomy-of-a-raw-transaction/markdown): Every Bitcoin transaction is a string of bytes: version, inputs, outputs, witness and locktime. Learn the layout and decode raw transaction hex.
- [PSBT v0 and v2: format versions, not network forks](https://mybitcoinexplorer.com/learn/psbt-v0-and-v2/markdown): Compare the original PSBT format with version 2, including input/output construction, modification flags and compatibility between signing tools.
- [CompactSize and VARINT: two different encodings](https://mybitcoinexplorer.com/learn/compactsize-and-varint/markdown): Decode Bitcoin CompactSize lengths with worked byte examples, distinguish Core’s internal VARINT format, and avoid unsafe parser assumptions.
- [What is the blockchain?](https://mybitcoinexplorer.com/learn/what-is-the-blockchain/markdown): The blockchain is Bitcoin's shared history: blocks of transactions, each linked to the one before by its hash. Learn how it works and why it is hard to change.
- [What is a block?](https://mybitcoinexplorer.com/learn/what-is-a-block/markdown): A Bitcoin block is a batch of transactions plus an 80-byte header that links it to the chain and proves the work done. See what is inside one.
- [The block header](https://mybitcoinexplorer.com/learn/block-header/markdown): The block header has six fields in 80 bytes: version, previous hash, merkle root, time, bits and nonce. Learn what each does and why miners hash it.
- [The genesis block](https://mybitcoinexplorer.com/learn/genesis-block/markdown): Block 0, mined on 3 January 2009, started the Bitcoin blockchain. Learn about its newspaper headline, its unspendable 50 BTC and how to view it.
- [Block height](https://mybitcoinexplorer.com/learn/block-height/markdown): Block height is a block's position in the chain, counting from 0 at the genesis block. Learn how heights schedule halvings, timelocks and confirmations.
- [Merkle trees and the merkle root](https://mybitcoinexplorer.com/learn/merkle-root/markdown): A merkle tree hashes a block's transactions in pairs until one hash remains: the merkle root. Learn how it works and how merkle proofs save space.
- [Block size and the weight limit](https://mybitcoinexplorer.com/learn/block-size-and-weight-limit/markdown): Bitcoin blocks are limited to 4,000,000 weight units, about 1.5 to 2.5 MB in practice. Learn why the limit exists and how it creates the fee market.
- [Block timestamps](https://mybitcoinexplorer.com/learn/block-timestamps/markdown): Miners set each block's timestamp within two rules: later than the median of the last 11 blocks, and at most 2 hours in the future. Learn why.
- [Stale blocks and chain reorganizations](https://mybitcoinexplorer.com/learn/stale-blocks-and-reorgs/markdown): When two miners find a block at once, nodes briefly disagree, then all switch to the longer chain. Learn how reorganizations work and what they mean for you.
- [The longest chain (most work) rule](https://mybitcoinexplorer.com/learn/longest-chain-most-work/markdown): Bitcoin nodes follow the valid chain with the most accumulated proof of work, not simply the most blocks. Learn why and how this creates agreement.
- [Duplicate transaction IDs and the BIP 30 rule](https://mybitcoinexplorer.com/learn/duplicate-transactions-bip30/markdown): Explore Bitcoin’s historical duplicate coinbase transactions, the UTXO overwrite problem, and why archival records need block context.
- [Median time past: Bitcoin’s shared time reference](https://mybitcoinexplorer.com/learn/median-time-past/markdown): Calculate median time past with an eleven-block example and understand why Bitcoin timelocks do not promise an exact wall-clock release time.
- [What is Bitcoin mining?](https://mybitcoinexplorer.com/learn/what-is-bitcoin-mining/markdown): Bitcoin mining is a worldwide race to find a rare hash. The winner adds the next block and earns new bitcoin plus fees. Try our mining simulator.
- [Proof of work](https://mybitcoinexplorer.com/learn/proof-of-work/markdown): Proof of work means a block's hash is so rare that finding it took huge effort, yet anyone can check it instantly. See how it secures Bitcoin.
- [The nonce](https://mybitcoinexplorer.com/learn/nonce/markdown): The nonce is a 4-byte number in the block header that miners change on every attempt. Learn why it runs out so fast and what miners change next.
- [Target and difficulty](https://mybitcoinexplorer.com/learn/target-and-difficulty/markdown): The target is the number a block hash must be below; difficulty says how much harder that is than the first target. Learn how both are calculated.
- [Difficulty adjustment](https://mybitcoinexplorer.com/learn/difficulty-adjustment/markdown): Every 2,016 blocks, about two weeks, Bitcoin resets mining difficulty so blocks average 10 minutes again. Learn the formula and the limits.
- [The block reward](https://mybitcoinexplorer.com/learn/block-reward/markdown): The block reward is what a miner earns for a block: the subsidy (new bitcoin) plus all transaction fees. See today's reward and how it is changing.
- [The Bitcoin halving](https://mybitcoinexplorer.com/learn/bitcoin-halving/markdown): Every 210,000 blocks the new bitcoin per block is cut in half. Halvings happened in 2012, 2016, 2020 and 2024; the next is due around 2028.
- [Mining pools](https://mybitcoinexplorer.com/learn/mining-pools/markdown): A mining pool combines many miners' hash power and shares the rewards, giving each small regular payouts instead of rare jackpots. Learn how pools work.
- [ASIC miners](https://mybitcoinexplorer.com/learn/asic-miners/markdown): ASIC miners are chips built only to compute SHA-256 as fast and efficiently as possible. Learn how they replaced CPUs and GPUs and what specs matter.
- [Hashrate](https://mybitcoinexplorer.com/learn/hashrate/markdown): Hashrate is how many hashes per second the Bitcoin network performs. It can't be measured directly; learn how it's estimated and why it matters.
- [The 51% attack](https://mybitcoinexplorer.com/learn/51-percent-attack/markdown): An attacker with most of the hash power could rewrite recent blocks and double spend their own coins, but could not steal coins or change Bitcoin's rules.
- [Hash functions](https://mybitcoinexplorer.com/learn/hash-functions/markdown): A hash function turns any data into a short, fixed-size fingerprint, and one changed letter changes it completely. Try it live and see how Bitcoin uses it.
- [SHA-256](https://mybitcoinexplorer.com/learn/sha-256/markdown): SHA-256 is the hash function Bitcoin uses for blocks, transaction IDs and mining, usually applied twice. Learn how it works and test it live.
- [HASH160 and RIPEMD-160](https://mybitcoinexplorer.com/learn/hash160-and-ripemd160/markdown): HASH160 is SHA-256 followed by RIPEMD-160. It turns a 33-byte public key into the 20-byte hash inside most Bitcoin addresses. See how and why.
- [Hexadecimal](https://mybitcoinexplorer.com/learn/hexadecimal/markdown): Hex writes each byte as two characters from 0-9 and a-f. Learn to read hashes, keys and raw transactions, and convert numbers with our tool.
- [Bytes and endianness](https://mybitcoinexplorer.com/learn/bytes-and-endianness/markdown): Bitcoin stores most numbers least-significant byte first (little-endian), which is why txids and block hashes look reversed in raw data. Learn why.
- [Digital signatures](https://mybitcoinexplorer.com/learn/digital-signatures/markdown): A digital signature proves you hold a private key without revealing it. Learn how Bitcoin signatures authorise every spend and why they can't be reused.
- [Elliptic curve cryptography](https://mybitcoinexplorer.com/learn/elliptic-curve-cryptography/markdown): Bitcoin keys live on the secp256k1 curve, y² = x³ + 7. Multiplying a point is easy and undoing it is practically impossible. See how it works.
- [ECDSA signatures](https://mybitcoinexplorer.com/learn/ecdsa/markdown): ECDSA is the signature scheme Bitcoin used from the start. A signature is two numbers, r and s. Learn how it works and why nonce reuse is fatal.
- [Schnorr signatures](https://mybitcoinexplorer.com/learn/schnorr-signatures/markdown): Taproot introduced Schnorr signatures: a fixed 64 bytes, simpler maths, batch verification and multi-party key aggregation. Learn what changed.
- [Randomness and entropy](https://mybitcoinexplorer.com/learn/randomness-and-entropy/markdown): A private key is only as safe as the randomness that made it. Learn what entropy means, how weak randomness led to real thefts, and how to stay safe.
- [Private keys](https://mybitcoinexplorer.com/learn/private-keys/markdown): A private key is a secret 256-bit number that controls your bitcoin. Learn what it looks like, how it creates addresses and how to keep it safe.
- [Public keys](https://mybitcoinexplorer.com/learn/public-keys/markdown): A public key is a point on the secp256k1 curve, calculated from your private key. Learn its formats, how it becomes an address and when it is revealed.
- [Bitcoin addresses](https://mybitcoinexplorer.com/learn/bitcoin-addresses/markdown): A Bitcoin address is a short code that tells a sender how to lock coins to you. It is not an account and holds no balance by itself. Learn how it works.
- [Bitcoin address types compared](https://mybitcoinexplorer.com/learn/address-types/markdown): Compare Bitcoin address types: Legacy (1…), P2SH (3…), native SegWit (bc1q…) and Taproot (bc1p…). See costs, compatibility and which to use.
- [Base58Check encoding](https://mybitcoinexplorer.com/learn/base58check/markdown): Base58Check writes data using 58 easy-to-read characters plus a 4-byte checksum that catches typos. Learn how legacy addresses and WIF keys are built.
- [Bech32 and Bech32m](https://mybitcoinexplorer.com/learn/bech32-and-bech32m/markdown): bc1 addresses use Bech32 (SegWit v0) or Bech32m (Taproot and later). They are lowercase, QR-friendly and catch typos. Learn how they are built.
- [Seed phrases (BIP 39)](https://mybitcoinexplorer.com/learn/seed-phrases-bip39/markdown): A seed phrase is 12 or 24 words that encode the randomness behind every key in your wallet. Learn how it works, and how to store it safely.
- [HD wallets (BIP 32)](https://mybitcoinexplorer.com/learn/hd-wallets-bip32/markdown): A hierarchical deterministic (HD) wallet derives an endless tree of keys from one seed, so a single backup restores everything. Learn how it works.
- [Derivation paths](https://mybitcoinexplorer.com/learn/derivation-paths/markdown): A derivation path like m/84'/0'/0'/0/0 says exactly where a key sits in an HD wallet. Learn how to read one and fix a restore that shows zero balance.
- [Extended public keys (xpub)](https://mybitcoinexplorer.com/learn/extended-public-keys-xpub/markdown): An xpub can generate every receiving address of a wallet account without being able to spend. Learn its uses and why you should keep it private.
- [WIF private key format](https://mybitcoinexplorer.com/learn/wif-private-key-format/markdown): WIF writes a single Bitcoin private key in Base58Check so it can be copied between wallets. Learn the format, the prefixes 5, K and L, and how to sweep.
- [Output descriptors: a wallet’s script blueprint](https://mybitcoinexplorer.com/learn/output-script-descriptors/markdown): Learn how Bitcoin output descriptors combine keys, derivation paths and script types, and why recovering keys alone may not recover a wallet.
- [Descriptor checksums: detect errors, not ownership](https://mybitcoinexplorer.com/learn/descriptor-checksums-and-recovery/markdown): Understand Bitcoin descriptor checksums, what they protect during backup and import, and why a valid checksum cannot authenticate a wallet policy.
- [Bitcoin Script](https://mybitcoinexplorer.com/learn/bitcoin-script/markdown): Every Bitcoin output is locked by a tiny program written in Script. Learn how locking and unlocking scripts work together and why Script is limited.
- [The stack](https://mybitcoinexplorer.com/learn/the-stack/markdown): Bitcoin Script runs on a stack: items go on top and operations take them off. Watch a simple script execute step by step with an animated diagram.
- [Script opcodes](https://mybitcoinexplorer.com/learn/opcodes/markdown): Opcodes are Bitcoin Script's instructions: duplicate, hash, compare, check signatures and times. A clear reference to the opcodes you will see most.
- [Pay to public key (P2PK)](https://mybitcoinexplorer.com/learn/p2pk/markdown): The earliest Bitcoin outputs locked coins directly to a public key. Learn how P2PK works, where to find it, and why it was replaced by P2PKH.
- [Pay to public key hash (P2PKH)](https://mybitcoinexplorer.com/learn/p2pkh/markdown): P2PKH locks bitcoin to the hash of a public key; to spend, you reveal the key and a signature. Step through the script with an animated diagram.
- [Pay to script hash (P2SH)](https://mybitcoinexplorer.com/learn/p2sh/markdown): P2SH locks bitcoin to the hash of a script that is revealed only when spending, giving complex conditions a short address. Learn how it works.
- [Multisig](https://mybitcoinexplorer.com/learn/multisig/markdown): Multisig requires several keys to sign, such as 2 of 3, removing single points of failure for theft and loss. Learn how to set it up safely.
- [Timelocks: CLTV and CSV](https://mybitcoinexplorer.com/learn/timelocks-cltv-csv/markdown): Timelocks stop bitcoin being spent until a set time. CLTV uses an absolute block or date; CSV counts from when the coins were received. See examples.
- [Segregated Witness (SegWit)](https://mybitcoinexplorer.com/learn/segwit/markdown): SegWit (2017) moved signatures into a separate witness section, fixing malleability, discounting signature data and making Lightning practical.
- [Taproot](https://mybitcoinexplorer.com/learn/taproot/markdown): Taproot (2021) lets complex Bitcoin spending conditions look like ordinary payments, using Schnorr signatures and hidden script branches. Learn how.
- [Witness data](https://mybitcoinexplorer.com/learn/witness-data/markdown): The witness is the part of a SegWit transaction holding signatures and unlocking data. It sits outside the txid and is discounted. Learn how it works.
- [OP_RETURN data outputs](https://mybitcoinexplorer.com/learn/op-return/markdown): An OP_RETURN output carries data and can never be spent, so it never bloats the UTXO set. Learn how it works, what it is used for and its limits.
- [What is the Bitcoin mempool?](https://mybitcoinexplorer.com/learn/what-is-the-mempool/markdown): The mempool is each node's waiting room for valid transactions not yet in a block. Learn how it works, why it fills up and how to read it live.
- [What is a Bitcoin node?](https://mybitcoinexplorer.com/learn/what-is-a-bitcoin-node/markdown): A Bitcoin node is a computer that checks every block and transaction against the rules. Learn what nodes do, why to run one and what it takes.
- [Full nodes vs pruned nodes](https://mybitcoinexplorer.com/learn/full-vs-pruned-nodes/markdown): A pruned node verifies everything an archival node does, then deletes old blocks to save disk space. Compare both and choose the right one.
- [The peer-to-peer network](https://mybitcoinexplorer.com/learn/peer-to-peer-network/markdown): Bitcoin nodes connect to a handful of peers and pass on new transactions and blocks, so news spreads worldwide in seconds. Learn how gossip works.
- [Initial block download (IBD)](https://mybitcoinexplorer.com/learn/initial-block-download/markdown): A new Bitcoin node must download and verify every block since 2009 before it is caught up. Learn what initial block download involves and how to speed it up.
- [Consensus rules](https://mybitcoinexplorer.com/learn/consensus-rules/markdown): Consensus rules decide what makes a Bitcoin block or transaction valid. Every node enforces them, and a block that breaks one is rejected. See examples.
- [Relay policy and standardness](https://mybitcoinexplorer.com/learn/relay-policy-and-standardness/markdown): Nodes apply extra rules about which transactions they relay and keep in their mempool. Learn how policy differs from consensus and why it matters.
- [Soft forks and hard forks](https://mybitcoinexplorer.com/learn/soft-forks-and-hard-forks/markdown): A soft fork tightens Bitcoin's rules so old nodes keep working; a hard fork loosens them so old nodes reject the new chain. Learn the difference.
- [Bitcoin Improvement Proposals (BIPs)](https://mybitcoinexplorer.com/learn/bitcoin-improvement-proposals-bips/markdown): BIPs are design documents proposing changes or standards for Bitcoin. Some change consensus; many just help wallets work together. See the key ones.
- [SPV and light clients](https://mybitcoinexplorer.com/learn/spv-light-clients/markdown): Light (SPV) clients download only block headers and check merkle proofs, trusting the most-work chain instead of verifying every rule. Learn the trade-offs.
- [Transaction indexes versus address-history indexes](https://mybitcoinexplorer.com/learn/txindex-and-address-index/markdown): See why a synced Bitcoin node may find blocks but need a separate index for transaction IDs, address history or complete explorer reports.
- [Keep Bitcoin Core RPC private](https://mybitcoinexplorer.com/learn/bitcoin-core-rpc-security/markdown): Learn why Bitcoin Core RPC is a privileged control interface, how it differs from public explorer APIs, and what authentication does and does not protect.
- [Compact block filters: find relevant blocks privately](https://mybitcoinexplorer.com/learn/compact-block-filters-bip157-bip158/markdown): Learn how BIP 157 and BIP 158 help light clients find potentially relevant blocks, why matches can be false positives, and what validation still remains.
- [Block files, chainstate and undo data](https://mybitcoinexplorer.com/learn/block-files-chainstate-and-undo/markdown): Understand the different jobs of Bitcoin Core’s block files, UTXO database, undo records and indexes before planning storage or recovery.
- [AssumeUTXO: snapshots and background validation](https://mybitcoinexplorer.com/learn/assumeutxo-snapshot-validation/markdown): Learn how Bitcoin Core boots from a recognized UTXO snapshot, what background validation still does, and why historical indexes can lag behind.
- [What is a Bitcoin wallet?](https://mybitcoinexplorer.com/learn/what-is-a-bitcoin-wallet/markdown): A Bitcoin wallet doesn't hold coins; it holds keys, finds the coins they control, and builds and signs transactions. Learn how to choose one.
- [Self-custody vs custodial](https://mybitcoinexplorer.com/learn/self-custody-vs-custodial/markdown): With self-custody you hold the keys and the responsibility; with a custodian such as an exchange, someone else does. Compare the risks and choose.
- [Hot and cold wallets](https://mybitcoinexplorer.com/learn/hot-and-cold-wallets/markdown): Hot wallets keep keys on an internet-connected device; cold storage keeps them offline and signs there. Learn how cold signing works and when to use it.
- [Hardware wallets](https://mybitcoinexplorer.com/learn/hardware-wallets/markdown): A hardware wallet stores your Bitcoin keys and signs transactions inside a dedicated device, so malware on your computer can't steal them. Learn how to use one.
- [How to back up a Bitcoin wallet](https://mybitcoinexplorer.com/learn/backing-up-a-wallet/markdown): Write your seed phrase on paper or metal, store it offline, never digitally, and test that recovery works. A step-by-step guide to Bitcoin backups.
- [The seed passphrase ("25th word")](https://mybitcoinexplorer.com/learn/seed-passphrase/markdown): An optional passphrase combines with your seed to create a different wallet, protecting you if the seed is stolen. Learn the benefits and the risks.
- [Address reuse and privacy](https://mybitcoinexplorer.com/learn/address-reuse-and-privacy/markdown): Every payment to a reused Bitcoin address is publicly linked. Learn why a fresh address each time protects your privacy and how wallets do it for you.
- [Coin control](https://mybitcoinexplorer.com/learn/coin-control/markdown): Coin control lets you choose exactly which UTXOs a Bitcoin transaction spends, for lower fees, better privacy and avoiding dust. Learn how to use it.
- [Watch-only wallets](https://mybitcoinexplorer.com/learn/watch-only-wallets/markdown): A watch-only wallet tracks balances and builds transactions from public keys only, so it can never spend by itself. Learn its uses and privacy cautions.
- [PSBT: prepare, inspect and sign a Bitcoin payment](https://mybitcoinexplorer.com/learn/psbt-signing-workflow/markdown): Follow a partially signed Bitcoin transaction through preparation, signing and finalization, with a worked fee example and clear privacy boundaries.
- [Why a pruned node cannot always rescan an old wallet](https://mybitcoinexplorer.com/learn/pruned-node-wallet-rescan/markdown): Understand the difference between validating old blocks and retaining them, and why wallet recovery can need historical data that a pruned node deleted.
- [The Lightning Network](https://mybitcoinexplorer.com/learn/lightning-network/markdown): Lightning is a network of payment channels on top of Bitcoin. Payments settle in seconds for tiny fees without a new on-chain transaction each time.
- [Payment channels](https://mybitcoinexplorer.com/learn/payment-channels/markdown): A Lightning payment channel is a 2-of-2 multisig output plus signed, unbroadcast transactions that record the latest balance. Learn how channels work.
- [Lightning routing](https://mybitcoinexplorer.com/learn/lightning-routing/markdown): Lightning payments hop through a path of channels chosen by the sender, wrapped in onion layers so each hop sees only its neighbours. Learn how routing works.
- [HTLCs: hash time-locked contracts](https://mybitcoinexplorer.com/learn/htlc/markdown): An HTLC pays someone who reveals a secret before a deadline and otherwise refunds the sender. It makes multi-hop Lightning payments trustless. See how.
- [Lightning invoices](https://mybitcoinexplorer.com/learn/lightning-invoices/markdown): A Lightning invoice is a payment request with the amount, payment hash, expiry and routing hints. Learn how BOLT 11 invoices and BOLT 12 offers work.
- [Channel liquidity](https://mybitcoinexplorer.com/learn/channel-liquidity/markdown): On Lightning you can only send what's on your side of a channel and receive what's on the other side. Learn how to manage inbound and outbound liquidity.
- [Closing channels and watchtowers](https://mybitcoinexplorer.com/learn/closing-channels-and-watchtowers/markdown): Lightning channels close cooperatively or by force. Watchtowers watch the blockchain and punish cheating while you are offline. Learn how closing works.
- [How to read a block explorer](https://mybitcoinexplorer.com/learn/how-to-read-a-block-explorer/markdown): A Bitcoin block explorer is a search engine for the blockchain. Learn what every field on a block, transaction and address page means, step by step.
- [How to look up a Bitcoin transaction](https://mybitcoinexplorer.com/learn/how-to-look-up-a-transaction/markdown): Find any Bitcoin transaction by its txid, read its status, fee and confirmations, and learn what to do when a transaction can't be found or is stuck.
- [What a Bitcoin trace can and can't prove](https://mybitcoinexplorer.com/learn/tracing-bitcoin/markdown): Following bitcoin from transaction to transaction is factual; claims about owners or which input paid which output are assumptions. Learn to read a trace.
- [Chain analysis heuristics](https://mybitcoinexplorer.com/learn/chain-analysis-heuristics/markdown): Chain analysis groups Bitcoin addresses using rules of thumb such as common-input ownership and change detection. Learn how they work and when they fail.