Bitcoin is the first decentralized cryptocurrency, running on a Proof of Work (PoW) network where computers compete to validate transactions by solving cryptographic puzzles. See how Bitcoin works for more on the fundamentals. The idea dates to a 2008 white paper, Bitcoin: A Peer-to-Peer Electronic Cash System, and it launched in 2009, created by the pseudonymous Satoshi Nakamoto.
A blockchain is a shared digital ledger that records transactions in cryptographically linked blocks maintained across a distributed network of computers. Because every participant holds a copy, and each block references the one before it, the history is transparent and extremely difficult to alter.
Censorship resistance is the property that makes it prohibitively difficult for any individual, group, or authority to block, alter, or suppress transactions and data. On public blockchains, no single party can stop a valid transaction from being recorded or prevent a user from reading the chain.
Crypto is the broad, informal term for the ecosystem of digital assets, applications, and networks built on blockchain technology, including cryptocurrencies, tokens, wallets, and decentralized apps. It is shorthand for the wider world of blockchain-based finance and ownership.
Crypto rails are the blockchain-based networks and decentralized financial (DeFi) infrastructure used to move value, much like traditional financial (TradFi) payment rails such as card networks or wire systems. They allow money and digital assets to settle directly on a blockchain, often faster than TradFi rails, and across borders without intermediaries.
A crypto wallet is software or hardware that stores the Private Keys used to access and manage your digital assets, letting you send, receive, and interact with crypto and decentralized apps. The wallet does not hold coins directly; it holds the keys that prove ownership on the blockchain.
Cryptography is the practice of securing information using mathematical techniques so it can be verified but not forged or tampered with. In blockchain, cryptographic methods link blocks, secure wallets, and prove ownership through public and Private Key pairs.
A DAO (decentralized autonomous organization) is a community-run entity whose rules and decisions are enforced by smart contracts rather than by managers or a central authority. Members typically hold tokens that let them propose and vote on how the organization operates.
Decentralization is the distribution of control and data across many independent participants instead of a single central authority. In blockchain, it means no one entity owns the network, which makes it more resilient, transparent, and censorship-resistant.
Decentralized apps (aka dapps) are applications that run on a blockchain using smart contracts rather than on servers controlled by a single company. While some dapps give users full control over their assets and data, many are hybrid, running core logic onchain while keeping the interface or data storage on traditional servers.
Decentralized Finance (DeFi) is a system of financial services such as trading, lending, borrowing, trading, and earning, built on public blockchains using smart contracts instead of banks or brokers. Anyone with a wallet can access these services permissionlessly, without opening an account.
Discord is a social media platform widely used by crypto and web3 projects to grow communities, coordinate members, share updates, and host support channels. It is a common gathering place for NFT communities and DAOs, though it can also attract scams, so verifying official links, profiles, and servers is essential in order to safely navigate it.
The double spend problem is the risk that the same digital money could be copied and spent more than once. Blockchains solve it by having a distributed network agree on a single, ordered transaction history, so once value is spent it cannot be reused.
Ether (ETH) is the native cryptocurrency of the Ethereum network, used to pay network fees (often called gas) and to help secure the network through staking. It is the second-largest cryptocurrency by market value as of 2026, and powers activity across Ethereum's apps and tokens.
Etherscan is a public block explorer for the Ethereum network, a website where anyone can look up transactions, wallet addresses, smart contracts, and token activity. It makes Ethereum's transparent, onchain data easy to search and verify.
Minting is the act of creating a new token or NFT and recording it on a blockchain for the first time. For NFTs, minting turns a digital file into a verifiable, ownable onchain asset; for tokens, it is how new units are issued.
A node is a computer that runs a blockchain's software, storing a copy of the ledger and helping validate and relay transactions. The more independent nodes a network has, the more decentralized and resilient it is.
A non-fungible token (NFT) is a unique, blockchain-verified token that proves ownership of a specific digital, or tokenized physical, item such as art, collectibles, or event tickets. Unlike interchangeable currencies, each NFT is one-of-a-kind and cannot be swapped one-for-one.
A Private Key is a secret code that proves a wallet address is yours and authorizes transactions from it. Anyone who has the Private Key controls the funds in the address it corresponds to, so it should never be shared.
Proof of Stake (PoS) is a consensus mechanism where validators lock up ("stake") cryptocurrency as collateral for the right to confirm transactions and add new blocks. It secures the network using economic incentives instead of the heavy energy use of Proof of Work, and it is how Ethereum operates today.
A protocol is the set of rules that governs how a blockchain network or application operates: how transactions are validated, how participants reach agreement, and how the system behaves. In DeFi, protocol also refers to specific applications like lending or trading platforms.
A public address is the shareable identifier that others use to send you crypto, similar to a bank account number. It is derived from your public key and can be safely shared, while the Private Key behind it stays secret.
A public blockchain is an open network that anyone can read, use, and help validate without permission. Its transparency and lack of a central gatekeeper are what make it censorship-resistant and trustworthy for shared record-keeping.
Public goods are resources that are openly available to everyone and not depleted by use. In web3 this often means open-source code, shared infrastructure, or protocols that benefit the whole ecosystem, and funding them sustainably is a major focus of many blockchain communities.
A Public Key is a cryptographic code generated from your Private Key that lets others confirm your transactions and serves as the basis for your public address. It can be shared openly without compromising your funds, unlike the Private Key.
A Secret Recovery Phrase (SRP, or seed phrase) is a list of typically 12 or 24 words that acts as the master key to your entire wallet and every account in it. Anyone with these words can access your funds, so it must be stored securely offline and never shared.
A self-custodial wallet allows the user alone to hold (or, custody) the Private Keys that control it, with total ownership over the assets inside it. No company or bank is to access or freeze assets in a self-custodial wallet. This gives full control and responsibility to the wallet holder themselves rather than a custodian or bank.
A smart contract is self-executing code stored on a blockchain that automatically carries out an agreement when its conditions are met, without needing an intermediary. Smart contracts power dapps, DeFi, NFTs, and DAOs by enforcing rules transparently and reliably.
Stablecoins are cryptocurrencies designed to hold a steady value by pegging to an asset such as the US dollar or the euro. They combine the fast, borderless transfer of crypto with price stability, making them widely used for payments, trading, and DeFi.
Web3 is a new phase of the internet built on public blockchains, where users own their money, data, and digital assets directly instead of storing them inside companies' accounts.
To understand web3, compare it to what came before. In web1, the internet was one-way, and most people could only read pages others published. The internet most of us use today is called web2; it lets anyone read, post, share, and interact, but almost always through platforms owned by companies that control your account, data, and content. Web3 keeps that ability to create and interact but changes who's in control: you own your identity and assets, not a company.
In practice, you use a self-custodial wallet, like MetaMask, as your login and account. A self-custodial wallet gives you ownership of your crypto and digital assets, helps prove who you are across apps, and lets you choose what to share—without a company in the middle. Because these apps run on public blockchains rather than private servers, it's harder for any single party to change the rules or lock you out.
Web3 is often used as an umbrella term to cover a wide range of activities, like payments, decentralized finance, NFTs, trading, and online communities.
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