One NFT is actually many things linked together.
Some of those things are stored on-chain while others are stored off-chain. This isn’t always the case, but for now we’ll pretend it is.
to mint an nft you need to first deploy a smart contract or use someone else's.
A smart contract is a set of instructions telling the blockchain how to mint, transfer, and burn tokens. Minting with someone else's contract has pros, like less transaction fees, but it could have cons, like less control of your assets. ERC-721 is an example of a smart contract.
tokens follow the rules of their contract and are always tied to it.
If two contracts have different instructions for things like minting or trading, their tokens will be incompatible. Some market's contracts bake-in additional features giving their tokens powers like royalties. However, those features may not work in other markets.
transfer_from = transfer_to
transfer_from ≠ trade_to
Tokens become non-fungible simply because their contract gives each new token a unique ID. Fungible tokens, on the other hand, share the same ID.
images are stored off-chain along with metadata.
Blockchains get slow when filled with giant files because every node has to store them. Instead, your token contains a link to metadata and the metadata contains a link to your media. Again, this isn’t always true, but let’s keep it simple.
you can host your assets with different levels of permanence.
If your image and/or metadata are only hosted in one place, they could become inaccessible if that place goes down. Because of this, distributed file storage is a good way to keep things around. If you are uploading and minting your NFT through a platform, they will typically make this choice for you.
If you aren't the one who owns the hosting account where your assets are stored, you may have limited control of them. This is great for convenience and potentially cost, but if you insist on complete ownership it's best to look into other options.
storage also affects how reliably your image can be found.
Browsers need a way to find and transfer your media and metadata so others can view it. These location protocols will impact how accessible your assets are far into the future.
When using a centralized cloud storage, the file only has one URL. If the file is moved or deleted from that location, the link will break forever. This is probably an oversimplification but that's the gist.
When using distributed storage, your file gets a unique id that isn't tied to a single location. If one of the locations (nodes) dissapears, you can simply call the file id from a different one.
all of these factors impact the energy consumption of your tokens.
Pinpointing exact energy metrics can be a challenge but the consensus mechanisms of the blockchain, the efficiency of your contract, and the storage of your assets all contribute to the footprint of your token.
there’s a lot to follow. skry is here to help.
We covered the basics but there's a lot of ways to build an NFT. In the future there will be many tokenized asset classes beyond digital art. Being informed is key so we’re building the tools to help you find the data about your tokens beyond “memability.”