Jonty Wareing - how NFT's actually reference the media you're 'buying'
I too have a lot of issues with this. What if your file moves? What if the file is fake? What if URLs change? What if servers shut down? Startups shut down or disappear all the time. And even if they don't people don't tend to do backwards compatibility anymore. This is a whole new and expensive consequence to link rot.
Short version:
The NFT token you bought either points to a URL on the internet, or an IPFS hash. In most circumstances it references an IPFS gateway on the internet run by the startup you bought the NFT from.
Oh, and that URL is not the media. That URL is a JSON metadata file