Bitcoin Explained: How BTC Works, Supply, Mining & Wallets

Bitcoin is both a peer-to-peer monetary network and the digital asset used on that network. It does not rely on a central bank to update account balances. Instead, transactions are authorized with cryptographic signatures, broadcast to a public network, grouped into blocks by miners, and independently checked by nodes that enforce Bitcoin's consensus rules.

For a beginner, the most useful way to understand Bitcoin is to separate four layers: the network rules, the BTC asset, custody of private keys, and the market price. A strong network does not make the price stable. A rising BTC price does not change how a private key works. And buying a spot Bitcoin exchange-traded product is not the same as holding bitcoin in your own wallet.

Key takeaways

Bitcoin usually refers to the network and protocol; BTC is the common market ticker for units of bitcoin.
Transactions use digital signatures and are recorded in a public ledger; miners propose blocks and nodes verify whether those blocks follow the rules.
Bitcoin's issuance schedule is defined in the protocol, with the block subsidy halving every 210,000 blocks and total supply converging toward about 21 million BTC.
A Bitcoin wallet manages private keys or seed material. It is more accurate to think of the ledger as recording spendable outputs than to imagine coins physically sitting inside a wallet app.
Direct BTC, custodial exchange balances, and spot Bitcoin ETP shares create different ownership, custody, fee, and operational risks.

What is Bitcoin?

Bitcoin is an open-source peer-to-peer network for transferring value according to a shared set of rules. The system was introduced by the pseudonymous Satoshi Nakamoto in the 2008 paper Bitcoin: A Peer-to-Peer Electronic Cash System, and the network launched in January 2009.

Bitcoin.org describes Bitcoin as a consensus network and decentralized peer-to-peer payment system. There is no company called “Bitcoin” that can unilaterally rewrite balances or issue extra BTC. Participants run compatible software and independently verify whether transactions and blocks follow the protocol rules.

This does not mean every part of the ecosystem is decentralized. Exchanges, wallet providers, mining pools, custodians, ETP sponsors, and other businesses can be centralized. The useful distinction is:

Layer	What it is	Main risk to check
Bitcoin network	The protocol, nodes, miners, blocks and consensus rules	Software/consensus and network assumptions
BTC asset	Units transferred under those rules	Market-price volatility and liquidity
Wallet/self-custody	Control of private keys	Key loss, backup failure, signing mistakes
Exchange/custodian	Third party controls keys on your behalf	Counterparty, withdrawal and operational risk
Spot Bitcoin ETP	Exchange-traded shares linked to bitcoin exposure	Product structure, tracking, fees and sponsor/custody risks

That separation prevents a common beginner mistake: treating “Bitcoin,” “a Bitcoin exchange account,” and “a Bitcoin ETF/ETP” as interchangeable things.

How does a Bitcoin transaction work?

At a high level, a Bitcoin transaction transfers control over spendable transaction outputs.

A simplified flow is:

A wallet identifies spendable bitcoin associated with keys it controls.
The wallet constructs a transaction specifying new outputs.
The transaction is digitally signed using the relevant private key material.
The transaction is broadcast to peers on the Bitcoin network.
Nodes check whether it follows the consensus rules and whether the referenced inputs are valid and unspent.
A miner may include the transaction in a candidate block.
Once a valid block containing the transaction is accepted by the network, the transaction has one confirmation. Additional blocks add more confirmations.

Bitcoin.org's technical overview emphasizes that private keys are used to sign transactions and that mining groups pending transactions into blocks that satisfy the protocol's cryptographic rules.

Bitcoin does not use traditional bank-account balances

Bitcoin is often explained as if every address has an account balance stored in one database row. The underlying model is different.

Bitcoin tracks unspent transaction outputs (UTXOs). A wallet can calculate a useful balance by finding the outputs that its keys are able to spend, but the protocol itself works by consuming existing outputs and creating new ones.

A simple analogy is paying a $30 bill with a $50 note: the old note is consumed and new outputs can represent the payment and the change. The analogy is imperfect, but it is closer to Bitcoin's transaction model than a conventional checking account.

What are confirmations, and when is a transaction final?

A Bitcoin transaction gets its first confirmation when it is included in a valid block. Each additional accepted block builds more proof of work on top of that history.

There is no universal rule saying that every transaction must wait exactly the same number of confirmations. The appropriate threshold depends on value, risk tolerance, transaction type and the receiving service's policy.

The important beginner distinction is:

Broadcast does not mean confirmed.
Seen in a wallet does not necessarily mean irreversible.
One confirmation means the transaction is in a block, not that all possible reorganization risk has mathematically become zero.
More confirmations generally make rewriting that transaction's history progressively more difficult.

Avoid turning “six confirmations” into a law of nature. It is a common operational convention for some higher-value uses, not a universal protocol requirement for every payment.

What do Bitcoin miners do?

Mining is Bitcoin's proof-of-work process for ordering transactions into blocks and making history expensive to rewrite.

Miners repeatedly hash candidate block data while changing values in search of a result below the network's current difficulty target. A valid result lets the miner propose a block. Other nodes then verify that block.

This creates an important division of roles:

Participant	Main role	What it cannot do alone
Wallet/user	Create and sign transactions	Force an invalid transaction into the accepted chain
Miner	Select valid transactions and compete to produce blocks	Rewrite consensus rules for validating nodes
Full node	Independently verify transactions and blocks	Guarantee that its preferred transactions are mined immediately
Mining pool	Coordinate hash power and distribute work/rewards	Make invalid blocks acceptable to nodes merely because the pool is large

So “miners validate Bitcoin” is incomplete. Miners perform proof of work and propose blocks; nodes independently validate whether those blocks obey the rules they enforce.

Where do new BTC come from?

A valid block may include a special coinbase transaction that lets the successful miner claim:

the current block subsidy, which creates new BTC according to the protocol's issuance schedule; and
transaction fees from transactions included in that block.

The block subsidy began at 50 BTC and is cut in half every 210,000 blocks. The 2024 halving reduced it from 6.25 BTC to 3.125 BTC per block.

Because each subsidy era issues fewer new units than the previous one, cumulative supply converges toward approximately 21 million BTC.

That supply rule is a protocol property. It does not mean:

21 million BTC are already circulating;
all issued BTC remain accessible;
every halving occurs on a fixed calendar date;
lower issuance guarantees a higher market price.

The dedicated Bitcoin halving-cycle guide owns the 2012/2016/2020/2024 comparison, 2028 mechanics, miner-economics interpretation and the limits of using halving history as a price model.

How do Bitcoin fees work?

Bitcoin transaction fees are not a fixed percentage of the amount sent.

A wallet generally chooses a fee based on the transaction's data size/weight and the fee market at the time. When block space is in higher demand, users may need to offer a higher fee rate for faster inclusion. When demand is lower, lower fee rates may confirm adequately.

This creates several counterintuitive results:

Sending $10,000 does not automatically cost more than sending $100.
A transaction that spends many small UTXOs can require more block space than a simple transaction moving a larger monetary amount.
An exchange withdrawal fee is an exchange policy and should not be confused with the Bitcoin network fee paid by an on-chain transaction.
A quoted “Bitcoin fee” without saying whether it means network fee, exchange fee, spread, ETP sponsor fee, or trading commission is incomplete.

What is a Bitcoin wallet?

A Bitcoin wallet is software or hardware used to manage the information needed to authorize Bitcoin transactions.

Investor.gov's current custody bulletin makes an important distinction: crypto wallets do not literally store crypto assets inside the device. They store or manage the private keys/passcodes used to access and control those assets.

For Bitcoin, the practical concepts are:

Private key / seed phrase: sensitive material used to derive or control signing keys.
Public key / address: information used in receiving and verifying transactions; addresses are not passwords.
Backup: a recovery method for restoring key control if a device is lost or damaged.
Self-custody: you control the relevant private keys.
Third-party custody: an exchange or custodian controls keys and gives you an account claim or service relationship.

Self-custody removes one risk and creates others

Self-custody can reduce dependence on a centralized exchange, but it transfers operational responsibility to the user.

If you lose the only usable backup of your keys, there is no central Bitcoin help desk that can reset them. If you sign a transaction to the wrong address, Bitcoin transactions are not designed with a bank-style chargeback process. If malware steals a seed phrase, the network cannot identify the theft and reverse it merely because the original owner objects.

That makes custody a risk-allocation choice, not a simple “safe vs unsafe” ranking.

Is Bitcoin anonymous?

Bitcoin is better described as pseudonymous than anonymous.

Transactions and addresses are visible on a public ledger. The blockchain does not directly display a passport name beside every address, but transaction history can be analyzed and addresses can sometimes be linked to people or entities through exchange records, address reuse, transaction patterns or other data.

Do not assume that a new address automatically provides strong privacy, or that every blockchain observer knows the real-world owner of every address. Both extremes are misleading.

Direct Bitcoin vs custodial Bitcoin vs spot Bitcoin ETPs

There are several ways to obtain price exposure to bitcoin, and they are not operationally identical.

Method	Do you control BTC private keys?	Where it is held/traded	Key distinction
Self-custodied BTC	Yes	Bitcoin network + your wallet	You manage key security and on-chain transactions
Exchange-held BTC	Usually no	Centralized exchange account	Exchange controls custody and withdrawals
Spot Bitcoin ETP shares	No	Securities brokerage / exchange	You own product shares, not a withdrawable BTC wallet balance

Investor.gov explains that spot Bitcoin ETPs hold bitcoin and seek to provide exchange-traded price exposure without requiring investors to personally transact through a crypto trading platform or manage private keys. It also notes that the product has its own sponsor fees, disclosures, tracking considerations and underlying-market risks.

So a spot Bitcoin ETP can simplify one custody layer for an investor, but it does not turn Bitcoin price exposure into a risk-free asset and it is not the same legal/operational object as directly controlled BTC.

What determines Bitcoin's price?

Bitcoin's protocol determines issuance rules. It does not set the market price.

Market price emerges from buyers and sellers across many venues. Important influences can include:

demand for direct BTC and investment products;
available market liquidity;
leverage and forced liquidations;
macroeconomic conditions and risk appetite;
regulatory or custody developments;
miner selling or treasury decisions;
market narratives and speculation.

This is why scarcity alone is not a complete valuation model. A fixed maximum supply does not tell you what one BTC “should” trade for next month or next year.

The crypto market-cycle guide owns broader regime analysis such as BTC leadership, crypto breadth, leverage and liquidity. This page stays with Bitcoin mechanics and ownership structure.

The main risks beginners should understand

1. Price risk

BTC can experience large drawdowns and rapid repricing. The network can continue operating normally while the market price falls sharply.

2. Custody risk

Exchange-held BTC introduces counterparty and withdrawal risk. Self-custody introduces key-management, backup and signing risk.

3. Transaction risk

On-chain transactions are not built around bank-style chargebacks. Wrong-address transfers, compromised keys and fraudulent instructions can be difficult or impossible to reverse.

4. Fee and congestion risk

Demand for block space changes. A fee that confirms quickly under quiet conditions may be inadequate during congestion.

5. Product-structure risk

Spot ETPs, derivatives and exchange balances can track or reference BTC while introducing separate fees, counterparties, leverage or tracking characteristics.

6. Interpretation risk

Bitcoin's limited supply, halvings or historical price performance do not create deterministic future returns.

A practical Bitcoin beginner checklist

Before buying, transferring or practicing with BTC, answer these questions:

What exactly am I using? Direct BTC, an exchange balance, a derivative, or an ETP share?
Who controls the private keys? Me, an exchange, a custodian, or an ETP's custody structure?
Which network and address am I using? Do not assume every asset labeled “BTC” on a platform represents an identical withdrawal path.
Which fees apply? Trading commission, spread, network fee, withdrawal fee, funding payment or sponsor fee?
What makes the transaction final enough for this use? A wallet notification is not the same as a confirmed block.
What can fail? Key loss, exchange outage, withdrawal restriction, fraud, price volatility, congestion or product tracking.
Am I studying Bitcoin mechanics or trading price action? Those are different skills.

For the trading-practice layer, the Bitcoin simulator checklist explains how historical replay differs from a wallet, exchange testnet or live execution. ChartMini is best suited for lightweight historical chart replay and price-action practice; it does not reproduce Bitcoin custody, blockchain settlement or exchange execution.

Frequently asked questions

What is Bitcoin in simple terms?

Bitcoin is an open peer-to-peer network and digital asset that lets participants transfer value without a central bank controlling the ledger. The network uses public transaction history, cryptographic signatures, proof-of-work mining, and consensus rules to determine which transactions and blocks are valid.

What is the difference between Bitcoin and BTC?

Bitcoin usually refers to the network, protocol, or broader system. BTC is the commonly used ticker for units of bitcoin traded on markets. The distinction is useful because the network and the market price of the asset are related but not the same thing.

Why is Bitcoin limited to about 21 million BTC?

Bitcoin's consensus rules reduce the block subsidy every 210,000 blocks. That declining issuance schedule converges toward a maximum supply of about 21 million BTC. The exact timing of future halvings depends on block production rather than a fixed calendar date.

What does Bitcoin mining actually do?

Mining competes to add valid blocks of transactions to Bitcoin's blockchain using proof of work. Miners do not decide the rules by themselves: nodes independently verify blocks and reject blocks that violate the consensus rules. Miners can receive the block subsidy and transaction fees when they produce a valid block.

Do Bitcoin wallets store bitcoin?

A wallet primarily manages the private keys or seed material used to authorize spending. The bitcoin itself is represented by spendable transaction outputs recorded on the Bitcoin ledger. Losing control of the relevant private keys can mean losing the ability to spend those funds.

Is a spot Bitcoin ETP the same as owning bitcoin directly?

No. A spot Bitcoin exchange-traded product gives investors exchange-traded exposure to the price of bitcoin through shares in a product that holds bitcoin. Direct bitcoin ownership involves the crypto asset itself and, if self-custodied, responsibility for private keys. The structures, fees, custody arrangements, and risks differ.

Can ChartMini store, send, mine, or buy Bitcoin?

No. ChartMini is a historical candlestick-replay tool for price-action practice. It does not provide a Bitcoin wallet, private-key custody, mining, blockchain transactions, exchange execution, or spot Bitcoin ETP trading.

Sources and verification notes

Bitcoin.org: Frequently Asked Questions — Bitcoin definition, consensus, issuance and general network mechanics.
Bitcoin.org: How Bitcoin Works — transactions, private keys, mining and block confirmation.
Bitcoin.org: Vocabulary — confirmation and halving terminology.
Bitcoin white paper — original peer-to-peer electronic cash design.
Investor.gov: Crypto Asset Custody Basics — current custody and private-key explanation.
Investor.gov: Bitcoin and Ether Exchange-Traded Products — direct crypto versus exchange-traded-product structure and risks.

Bitcoin Explained: How BTC Works, Supply, Mining, Wallets & Risks