How NFTs Work, Technically

Once you're past "NFTs are unique tokens," the useful question is how — because the technical details determine what you actually own and how durable it is. This goes under the hood.

Token standards

NFTs follow shared standards so wallets and marketplaces can handle them consistently. On Ethereum, the dominant ones are:

• ERC-721 — the classic standard where each token is unique and individually tracked.
• ERC-1155 — a more flexible standard that can manage many token types (both unique and identical) in one contract, popular in gaming.

Other chains have their own equivalents. The standard defines how ownership is recorded and transferred on-chain.

What's actually on the blockchain

Here's the part that surprises people: the blockchainA shared, tamper-resistant digital ledger that records transactions across many computers at once. usually stores the token and a pointer, not the image itself. The token records ownership and links to metadata (the name, traits, and a link to the media). That media often lives elsewhere — ideally on decentralized storage like IPFS, sometimes on a regular web server.

The durability question

This matters for what you really own. If the metadata or media is hosted on a private server that goes offline, the token persists but the thing it points to can vanish — a "broken" NFTA non-fungible token — a unique, blockchain-verified record of ownership of a digital (or linked physical) item.. Projects that store metadata and media on decentralized, content-addressed storage are far more durable. Before valuing an NFT, it's worth knowing where its data actually lives.

Minting

Minting is the act of creating the token on-chain — writing that first ownership record. It costs a network gas fee and is how an NFT comes into existence, whether you mint from a project's contract or it's created when first sold.

Key takeaways

• NFTs follow token standards (e.g., ERC-721 for unique tokens, ERC-1155 for mixed/gaming) that define ownership on-chain.
• The blockchain typically stores the token and metadata pointer — not the image itself.
• Media and metadata often live off-chain; decentralized storage (like IPFS) makes an NFT far more durable.
• An NFT whose data sits on a private server can "break" if that server goes offline.
• Minting is the on-chain act of creating the token, and it costs a gasThe fee paid to process a transaction on a blockchain like Ethereum. fee.