It sounds like you're describing a portable FTP client that connects to a large online movie server.
FTP is one of the oldest protocols on the internet, but it persists for a reason: efficiency. ftp biggest online movie server all portable
Copyright: Be aware of the digital rights laws in your country regarding downloaded content. It sounds like you're describing a portable FTP
This report details the history of FTP movie servers, why the "biggest" servers disappeared, and the modern alternatives for portable movie storage. Professional screening kit: This report details the history
Below is a drafted article exploring how these servers work, what to look for, and how to maintain portability.
VLC Media Player: Did you know you can stream an FTP link directly in VLC? Just go to Media > Open Network Stream. 🔍 Pro-Tip: How to Find Servers
ftp://username:password@your-ddnshost:21/path/to/movie.mkv