What Is an NFT?

A non-fungible token (NFT) is a unique cryptographic token on a blockchain that represents ownership of a specific item. Unlike Bitcoin (where every BTC is identical and interchangeable), each NFT is unique — no two are the same.

"Non-fungible" simply means not interchangeable. A $10 bill is fungible — any $10 bill equals any other. A first-edition signed book is non-fungible — it's unique.

NFTs can represent: digital artwork, music, video clips, virtual real estate, game items, collectibles, domain names, event tickets, and more.

How NFTs Work on the Blockchain

Most NFTs are built on the ERC-721 or ERC-1155 token standards on Ethereum (or similar standards on Solana, BNB Chain, etc.):

  • A smart contract is deployed defining the NFT collection rules
  • Each token has a unique ID and metadata (name, image URL, attributes)
  • Ownership is recorded on-chain — publicly verifiable by anyone
  • Transfer of ownership is a signed blockchain transaction

Important distinction: The blockchain records ownership, but usually not the actual media file (which is too large). The image/video is typically stored on IPFS or a server. If that server disappears, the NFT's linked content may be gone — though the token itself remains.

How Your Wallet Stores NFTs

Your wallet doesn't store the NFT file — it stores the private key that proves ownership of the token ID in the smart contract. When you view your NFTs in a wallet app:

  • The wallet queries the blockchain for all token IDs associated with your address
  • It fetches the metadata (image URL, attributes) from the token's URI
  • It displays the images by loading them from IPFS or a web server

Wallets with good NFT support include MetaMask, Rainbow, Trust Wallet, and Phantom (for Solana NFTs).

NFT Marketplaces

  • OpenSea — Largest multi-chain NFT marketplace
  • Blur — Professional trading platform for Ethereum NFTs
  • Magic Eden — Leading Solana NFT marketplace
  • Rarible — Multi-chain, creator-focused
  • Foundation — Curated art NFTs

NFT Security Risks

  • Approval exploits: "setApprovalForAll" grants a contract permission to transfer all your NFTs. Be extremely cautious about what you approve.
  • Phishing mints: Fake mint sites for cloned collections drain wallets via malicious contracts.
  • Airdropped malicious NFTs: Receiving an unsolicited NFT is not necessarily safe — interacting with it (clicking "claim" or visiting linked URLs) can trigger drainers.
  • Counterfeit collections: Fake collections mimicking famous ones at lower prices. Always verify the contract address on the official project website.

Never interact with NFTs you didn't buy or request. Some malicious NFTs are designed so that even attempting to transfer or burn them triggers a wallet drain.

Long-Term NFT Storage

For valuable NFTs, consider a hardware wallet. The same principles apply as with fungible tokens — cold storage keeps private keys offline and immune to remote theft. Ledger and Trezor both support NFT storage through their companion apps.