Json files are stored in the blockchain, these are files that are no more than 23KB in weight, it depends on the internet connection how long you need to get this Json file in the original source. The costs vary based on the size of the blockchain, but are much cheaper than a cloud. You have to understand it that way. You have your own server over which you upload a PDF, this PDF file is converted into a JSON file and stored in the blockchain. If you switch off the server, your data will still remain in the blockchain.

With your private key, you always have access to your files, which, as I said, remain in the blockchain even when your server is off