From title of this thread I can say CATA is about flow blockchain that is providing decentralized cloud storage. But what does middle ware says here? Please dont say that read whitepaper to learn about it, I need a short answer here.
Don't think OP is interested in your question. Middle ware may refer to storage media that holds NFTs that are hosted on blockchain. Middleware is usually a software that provides interoperability and CATA is trying to give interoperability b/w blockchain and the storage media.