What are the key terms to know in NFTs and Web3?

Non-Fungible Tokens (NFTs) are unique, digital items with blockchain-managed ownership. Examples of NFTs include digital art, collectibles, virtual reality items, crypto domain names, ownership records for physical assets, and more. To learn more about NFTs, check out our Learn Center.

A blockchain is a digitally distributed ledger that facilitates the process of recording transactions and information across a network. You can think of it as a decentralized or distributed database. OpenSea supports a number of blockchains.

“Bridging” your cryptocurrency from one chain to another allows you to use the same funds across multiple blockchain networks.

A collection is a body of work, like a store or art gallery.

A crypto wallet is an application or hardware device that allows individuals to store and retrieve digital items, like cryptocurrency and NFTs.

A cryptocurrency is a digital currency in which transactions are verified and records maintained by a decentralized system using cryptography, rather than by a centralized bank or government. The core cryptocurrencies you can use on OpenSea are Ethereum (ETH/WETH), AVAX, USDC, KLAY, and DAI.

A blockchain-integrated website that requires you to connect and approve all transactions with your wallet signature. Examples include OpenSea, Uniswap, Zapper.fi.

A DAO is a decentralized autonomous organization in web3. Instead of having a centralized governing body, DAO members or token holders vote to make decisions.

DeFi describes peer-to-peer financial services on blockchains, enabling open markets.

NFT drops enable community members and buyers to mint NFTs from brand-new collections for the first time.

The Ethereum Name Service (ENS) is a domain naming system based on the Ethereum blockchain. ENS domains resolve to wallet addresses, meaning you can send NFTs and cryptocurrency to them.

The ERC-721 token standard enables “1 of 1” NFTs to be created. Each item is unique, with only one copy.

Also known as semi-fungible NFTs, ERC-1155 tokens can have multiple copies of the same NFT.

Ethereum is a blockchain, and ETH is the currency used to make transactions on the Ethereum blockchain.

If a blockchain is EVM-compatible it means it is technically compatible with Ethereum, and tokens can be transferred between them. An example of an EVM-compatible blockchain is Polygon. Just because a blockchain is EVM-compatible does not mean you can directly send tokens from one chain to another. Tokens must be bridged across to the other chain.

Floor price is the lowest price for a collection's items, rather than the average item price, and is updated in real time.

Think of gas fees as Ethereum blockchain transaction costs. OpenSea has no say in setting gas fees – they are determined by supply and demand across the network (blockchain).

Gwei describes a very small amount of ETH, the equivalent of 1 billionth of 1 ETH. It helps measure gas fees, or transaction costs, on the Ethereum blockchain, which are generally smaller relative to USD than ETH itself.

“Layer 2” blockchains are built on top of other blockchains. For example, Base is a Layer 2 blockchain built on Ethereum.

NFT metadata is the digital information tied to an NFT. For example, metadata could include information about the traits of that NFT.

Minting an NFT describes creating a new NFT on the blockchain. This can be done by the creator, minting it into their own wallet, or by buyers participating in a drop.

In a proof-of-work blockchain system, such as Bitcoin, decentralized computers solve an encryption puzzle to validate transactions.

In a proof-of-stake blockchain system, such as Ethereum, decentralized computers validate transactions based on the amount of funds “staked” (or collaterized) on that chain.

This describes a “tip” that is set automatically to compensate validators for executing transactions on Ethereum.

A string of numbers (often 256 characters long) that represents your signature to authorize transactions on the blockchain.

A “rarity” ranking describes the relative scarcity of one NFT’s trait compared to another in the same collection. OpenSea uses the OpenRarity standard.

Your seed phrase is a list of words (usually ranges from 12-24 words) that can be used to recover your crypto should you forget your password or lose access to your wallet. When you first begin using your wallet, find your seed phrase and back it up somewhere safe, in multiple locations if possible. You’ll receive a seed phrase to write down when you first create a crypto wallet. This is how you can back up your key without actually holding the numbers. Also known as a "mnemonic phrase" or “secret recovery phrase.” Don’t store your seed phrase on an online cloud storage service and never share it with anyone.

Smart contracts are decentralized code that run on blockchains. dApps are powered by smart contracts - buying and selling NFTs using OpenSea utilizes the Seaport smart contract protocol.

The OpenSea swap feature allows you to swap one crypto token for another – for example, ETH for MATIC.

Also known as your "public key." Your wallet address is unique. It’s the address people will use when sending you cryptocurrency or NFTs. Your NFTs and cryptocurrency do not live in your wallet—they exist on the blockchain, under your wallet address. Your software or hardware wallet only contains the key to that address. On Ethereum, your address starts with a "0x". You can also use an ENS domain.