DEFINITION
Minting means creating a new NFT. Recall that NFT stands for non-fungible token. Just as a metal coin must be minted in the real world, a non-fungible token must be minted digitally. The token is minted on a blockchain such as Ethereum, a public database where it can be stored, traced, and traded. To mint a token is to create a new entry in that database.
In most cases, the true NFT – the piece stored on the blockchain – is just a few lines of code, and does not actually contain the content that is of value, such as a picture, video, or song. That's because storing content on a blockchain is usually quite expensive. In most cases, content is stored elsewhere, and the proper NFT just contains a reference to this content.
Therefore, minting an NFT is often a dual process in which the creator uploads the file for hosting while simultaneously creating a token referencing it on the blockchain. Minting services try to make this process simple for users and may not make the distinction clear. Depending on the service, they may host the NFT on their own servers for convenience.
This disconnect is one huge issue in current NFT technology. When minting an NFT, it is important to know where the content will be hosted, so you can consider how safe and trustworthy that source is. URLs are considered risky addresses, because whoever owns the URL can change what it points to.
For this reason, many people prefer to see NFTs stored using a process called content-addressing on a network such as IPFS or Swarm, which ensures that the link can only ever point to that unique piece of content. Even this approach has issues though, as items stored on such networks must still be hosted and maintained to exist in the future.
When minting (or purchasing) an NFT, make sure you know where the content will live, and that you trust that it will live there for a long time. Otherwise, the buyer may get stuck with owning a permanently broken link.