Bitcoin (BTC) is the first and best-known cryptocurrency — the asset that started the entire digital-asset industry. Almost everyone has heard of it, yet far fewer people understand how Bitcoin actually works, where new coins come from, why there will never be more than 21 million of them, and what risks come with holding BTC. That gap has produced plenty of myths: some call Bitcoin “digital gold”, others call it a bubble, and others still believe it is anonymous money for shady deals.
This Bitcoin review is written for beginners who want to understand the basics before their first purchase, and for existing holders who want to put their knowledge in order. We do not give investment advice or make price predictions. The goal is simple: to help you understand how the network is built and where its real strengths and weaknesses lie.
You will learn who created Bitcoin and how the network evolved, how mining and proof of work function, what the halving is, which address formats exist, why fees rise, what the Lightning Network is for, who BTC suits (and who it does not), and how to buy and store it safely.
- What is Bitcoin
- Bitcoin history: key dates
- How the Bitcoin network works
- Supply, the 21 million cap and the halving
- BTC key specs: table
- Addresses, transactions and fees
- SegWit, Taproot and the Lightning Network
- Bitcoin pros and cons
- Who Bitcoin is for — and who it is not for
- How to buy and store BTC
- Risks you should know about
- FAQ
- Conclusion
- Sources
What is Bitcoin
Bitcoin is a decentralized digital currency and, at the same time, an open payment network with no central bank, owning company or administrator. Every transaction is recorded in a public, distributed ledger — the blockchain — and thousands of independent nodes around the world keep a copy of it. Because of this, anyone can verify the history of any transfer, and rewriting that history after the fact is practically impossible.
By convention, “Bitcoin” with a capital B refers to the network and protocol, while “bitcoin” or the ticker BTC refers to the coin itself. One coin is divisible into 100 million smallest units called satoshis (sats). You do not need to buy a “whole bitcoin”: you can purchase any fraction, such as 0.001 BTC.
The core idea behind Bitcoin is to let people transfer value directly, without intermediaries they have to trust. The rules of the network live in open-source code, and nobody can change them unilaterally. Upgrades only take effect when a significant share of participants — nodes, miners and users — support them.
Bitcoin history: key dates
On October 31, 2008, a person or group using the pseudonym Satoshi Nakamoto published “Bitcoin: A Peer-to-Peer Electronic Cash systеm”, the Bitcoin white paper. It described an electronic cash systеm that solves the double-spending problem without a trusted third party. Satoshi’s real identity has never been officially confirmed.
On January 3, 2009, the first block — the genesis block — was mined. Satoshi embedded a headline from The Times about bank bailouts in its data, widely read as a comment on the 2008 financial crisis. In 2010 came the famous purchase of two pizzas for 10,000 BTC, still celebrated every May 22 as Bitcoin Pizza Day. By the end of 2010, Satoshi had stepped away and handed development over to the community.
Important technical and market milestones followed: SegWit activated in August 2017, the Lightning Network went live on mainnet in 2018, and the Taproot upgrade activated in November 2021. In January 2024, the US Securities and Exchange Commission approved the first spot Bitcoin exchange-traded funds, and the fourth halving took place in April 2024. In March 2026, the 20 millionth bitcoin was mined, meaning roughly 95% of the maximum supply is already in circulation.
How the Bitcoin network works
Bitcoin uses a consensus mechanism called Proof of Work. Miners bundle unconfirmed transactions into a block and try billions of variations to find a SHA-256 hash that meets the current difficulty target. The first miner to find a valid solution adds the block to the chain and receives a reward: newly issued coins plus the fees from the transactions in that block.
On average, a new block is found roughly every 10 minutes. To keep that interval stable no matter how much mining power joins or leaves, the network automatically recalculates the difficulty every 2,016 blocks (about two weeks). More hash power makes the puzzle harder; less hash power makes it easier.
Each block references the hash of the previous one, so altering an old record is practically impossible: an attacker would have to redo the work for that block and every block after it while outpacing the rest of the network. That is why a transaction is considered more secure the more confirmations it has. Many services wait for one to six confirmations before crediting BTC.
Full nodes play an equally important role. They do not mine coins, but they independently validate every block and transaction against the protocol rules. If a miner tries to inсlude an invalid transaction, the nodes simply reject the block. Anyone can run their own node on an ordinary computer.
Supply, the 21 million cap and the halving
The maximum number of bitcoins is hard-coded into the protocol: there will never be more than 21,000,000 BTC. New coins are created only as a reward to miners for producing blocks, and that reward is cut in half every 210,000 blocks — roughly every four years. This event is known as the halving.
In 2009, the block reward was 50 BTC. After the November 2012 halving it dropped to 25 BTC, in July 2016 to 12.5 BTC, in May 2020 to 6.25 BTC, and after the halving on April 20, 2024 (block 840,000) to 3.125 BTC. The next cut is expected at block 1,050,000, most likely in 2028. We explain the mechanism in detail in our article on the Bitcoin halving.
Predictable, declining issuance is one of the reasons Bitcoin is often compared to gold. It is important to understand, however, that limited supply alone does not guarantee a rising price. BTC’s value depends on demand, liquidity, macroeconomics, regulation and market sentiment, so the price can move sharply in either direction.
As the block subsidy shrinks, transaction fees will make up a growing share of miners’ revenue. The last fractions of a bitcoin are expected to be mined around the year 2140, after which network security will have to be funded by user fees alone.
BTC key specs: table
| Parameter | Value |
|---|---|
| Ticker | BTC |
| Creator | Satoshi Nakamoto (pseudonym) |
| White paper | October 31, 2008 |
| Network launch | January 3, 2009 (genesis block) |
| Consensus | Proof of Work, SHA-256 algorithm |
| Average block time | About 10 minutes |
| Maximum supply | 21,000,000 BTC |
| Block reward | 3.125 BTC (since April 2024) |
| Difficulty adjustment | Every 2,016 blocks |
| Smallest unit | 1 satoshi = 0.00000001 BTC |
| Address formats | 1… (Legacy), 3… (P2SH), bc1q… (SegWit), bc1p… (Taproot) |
Addresses, transactions and fees
Bitcoin has several address formats, and they are all compatible: any modern wallet can send BTC to any valid address. Addresses starting with 1 are the original Legacy format. Addresses starting with 3 are P2SH and are often used for multisig. Addresses starting with bc1q are native SegWit and usually mean lower fees. Addresses starting with bc1p use the Taproot format.
A Bitcoin fee does not depend on the amount you send, but on the transaction size in virtual bytes and on how busy the network is. When many people want to get into the next block, they compete on fee rate and fees go up. Unconfirmed transactions wait in a queue called the mempool. If your fee was too low, a transaction can sit there for hours. Our guide to Bitcoin fees and the mempool explains how to avoid that.
Bitcoin transactions are irreversible. If you send coins to the wrong address, there is no way to cancel the transfer; you can only get the funds back if the recipient voluntarily returns them. Always check the full address before sending — not just the first and last few characters — because look-alike address attacks do exist.
Keep in mind that Bitcoin is pseudonymous, not anonymous. Names are not stored on the blockchain, but every transfer is public, and once an address is linked to a real identity (for example, through an exchange with identity verification), its transaction history can be traced.
SegWit, Taproot and the Lightning Network
Bitcoin’s base layer is deliberately conservative: blocks are infrequent and their capacity is limited. This helps preserve decentralization but caps throughput. For that reason, the community evolves the network gradually through backward-compatible upgrades.
SegWit
Segregated Witness (SegWit), activated in August 2017, moved signature data into a separate structure. It fixed transaction malleability and made more efficient use of block space, which is why SegWit transactions usually cost less.
Taproot
Taproot, activated in November 2021, introduced Schnorr signatures and improved how complex spending conditions work. For users, this means more compact and private multisig and sсript-based transactions; for developers, it opens more room to build on top of Bitcoin.
Lightning Network
The Lightning Network is a network of payment channels built on top of Bitcoin. Users open a channel with one on-chain transaction and can then make many fast, low-cost payments inside it, with the final balance settled on the blockchain when the channel closes. Lightning works well for small and frequent payments but requires some understanding of channels and liquidity. Read more in our Lightning Network explainer.
Bitcoin pros and cons
Advantages
- The longest track record. The network has been running since 2009 and has survived many crises, attacks and market cycles.
- High decentralization. No company can single-handedly change the rules or block transfers at the protocol level.
- Transparent, capped issuance. The 21 million limit and the halving schedule are known in advance.
- Deep liquidity. BTC trades on virtually every exchange and is supported by most swap services and wallets.
- Institutional recognition. Regulated Bitcoin investment products exist, including spot ETFs.
Disadvantages
- High volatility. The price can change dramatically within days or even hours.
- Limited base-layer throughput. During busy periods, fees rise and confirmations slow down.
- Limited programmability. Bitcoin’s scripting language is intentionally simple, so complex applications are built on other networks or on additional layers.
- Mining energy use. Proof of Work requires significant computing resources, which draws environmental criticism.
- Mistakes are final. Lost keys or a wrong address usually mean the funds are gone for good.
Who Bitcoin is for — and who it is not for
Bitcoin may suit people who want to get to know crypto through its most established asset; those considering long-term holding of a small portion of their savings who can stomach sharp price swings; people who value independence from intermediaries and the ability to hold their own funds; and those who need to move value across borders without relying on banking infrastructure.
Bitcoin is probably not a good fit for anyone who needs a stable value for everyday payments — stablecoins pegged to the dollar or another fiat currency are more practical for that. It is also a poor choice for people chasing quick profits, those unwilling to learn how to manage private keys, or anyone investing money they cannot afford to lose.
For smart-contract developers and heavy DeFi users, Bitcoin’s base layer is also limiting — those use cases are more commonly served by Ethereum and other programmable networks.
How to buy and store BTC
You can buy Bitcoin on a centralized exchange, from peer-to-peer sellers, through exchange-traded funds (where available in your jurisdiction), or by swapping another cryptocurrency for BTC. If you already hold USDT, for example, the simplest route is to swap it for Bitcoin through an instant exchanger and receive the coins straight to your own wallet. Our step-by-step guide on how to buy Bitcoin covers every method.
The basic process looks like this:
- Choose a wallet. A mobile non-custodial wallet is fine for small amounts; a hardware wallet is better for larger sums.
- Back up your seed phrase offline. Write it on paper or a metal plate, and never store it in photos, cloud storage or messengers.
- Get your BTC address. Copy the receiving address from your wallet, ideally in bc1q or bc1p format.
- Pick a buying or swap method. Compare the final amount you will actually receive after all fees.
- Send a test transaction. For your first transfer, send a small amount and confirm it arrives.
- Track it in a block explorer. Use the transaction hash to follow the number of confirmations.
- Withdraw from the exchange. If you bought on an exchange and do not plan to trade, move your BTC to your own wallet.
On RubyCash you can swap USDT, ETH and other coins to BTC without registration: just enter the amount and your wallet address. We explain the difference between custodial and non-custodial options in detail in our article what is a crypto wallet.
Exchange USDT to BTC
Risks you should know about
Market risk. Bitcoin has historically gone through drawdowns of tens of percent. Only invest an amount you could afford to lose, and avoid leverage unless you fully understand how margin trading works.
Custody risk. If you keep BTC on an exchange, you are trusting that platform with your funds: it can freeze withdrawals, get hacked or go bankrupt. If you hold coins yourself, responsibility for the seed phrase rests entirely with you.
Scams. Bitcoin attracts many schemes: fake wallets, phishing sites, “coin doublers” and fake support agents. No legitimate person or service will ever ask for your seed phrase.
Regulatory risk. Tax rules, identity-verification requirements and the availability of services vary by country and can change. Before buying, check how crypto is regulated where you live.
FAQ
Bitcoin was created by a person or group using the pseudonym Satoshi Nakamoto. The white paper was published in 2008 and the network launched in January 2009. Satoshi’s real identity has never been officially confirmed.
The maximum supply is capped by the protocol at 21 million BTC. New coins are issued as a mining reward that halves every 210,000 blocks. The final fractions of a bitcoin are expected to be mined around 2140.
Yes. One bitcoin is divisible into 100 million satoshis, so you can buy any fraction, for example 0.0005 BTC. The minimum amount depends on the rules of the specific exchange or swap service.
A new block is found about every 10 minutes on average, so the first confirmation usually arrives within 10 to 30 minutes. When the network is busy and the fee is low, the wait can be longer. Many services credit BTC after several confirmations.
No, Bitcoin is pseudonymous. Names are not stored on the blockchain, but all transactions are public, and once an address is linked to a person, their transaction history can be traced. Real privacy requires extra discipline and dedicated tools.
The halving is an automatic 50% cut in the block reward that happens every 210,000 blocks. The most recent halving took place in April 2024, reducing the reward to 3.125 BTC. The next one is expected around 2028.
These are different address formats: Legacy, P2SH, native SegWit and Taproot. They all belong to the same Bitcoin network and are compatible with each other. The newer bc1q and bc1p formats usually let you pay lower fees.
For long-term storage of larger amounts, many people choose a hardware wallet with a seed phrase backed up offline. For small amounts, a reputable non-custodial mobile wallet works well. Keeping coins on an exchange is convenient for trading but means trusting a third party.
A confirmed transaction cannot be cancelled. While a transaction is still unconfirmed, some wallets let you rеplace it with a higher fee, but this does not always work. That is why you should double-check the address and amount before sending.
Conclusion
Bitcoin remains the foundation of the crypto industry: it has the longest operating history, transparent issuance rules, strong decentralization and broad market support. For many people, BTC is the first crypto asset they ever own and the entry point into digital money.
At the same time, Bitcoin has real limitations: high volatility, fees that spike during peak demand, limited base-layer programmability and the irreversibility of mistakes. Understanding these trade-offs matters far more than any price forecast.
If you decide to hold BTC, start with a reliable wallet and a properly backed-up seed phrase, send test transactions and always verify addresses. That approach lets you use Bitcoin knowingly and safely.