An NFT's metadata is like its digital identity token.

They indicate its name, what image it has, what makes it special, what level of rarity it has or what collection it belongs to.

It is the information that makes an NFT not just a number, but something with its own identity, value and characteristics that distinguish it from others.

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Los NFT metadata are data structures, usually in format JSON, which contain all the descriptive information associated with a non-fungible token.

This metadata is not part of the contract code, but is essential to represent the content, identity and properties of the NFT.

The most common fields include:

• Name (token name)
• Description (description of your purpose or story)
• Image (URL of the image or multimedia content)
• Attributes (a list of characteristics such as rarity, color, level, etc.)
• external_url or custom properties

The function URI token () In contracts ERC-721 or ERC-1155 it is used to link each TokenID with its corresponding metadata.

This metadata may be stored On-chain (within the blockchain itself, although with space and cost limitations) or Off-chain, in decentralized solutions such as IPFS (InterPlanetary File System), Arweave or even centralized servers in less sophisticated collections. Marketplaces such as OpenSea, LooksRare or Blur read this metadata to display NFTs visually, sort them by rarity, or filter by attributes.

In addition, they are essential in gamified environments, metaverses or utility projects, since they allow each token to be linked to functions, levels, statistics or accesses.

Poor management of metadata (for example, that is modifiable without control or dependent on a centralized server) can compromise the trust, value and permanence of an NFT.

Therefore, good practices include the use of immutable content hashes (CID), validated JSON structure, and decentralized storage.

In short, metadata gives meaning, visual, narrative and functional value to an NFT, and is as important as the token itself in the Web3 experience.