[hombre_fatal]

One practical difference is that all the parts of a "collection" are individually addressable in IPFS.

For example, unlike torrents, you can seed a collection like "My Web Show (All Seasons)" and add new files as new episodes become available. With torrents, you have to repackage them as new torrent files. IPFS also then encourages file canonicalization instead of everyone seeding their own copy of a file.

[georgyo]

This is a over simplification I think. In IPFS to add a file to a folder, you need to rebuild that folder which changes the address. You still need to get people to access the new address to see any updates. IPNS makes that fairly easy, but a similar technology could be made for bittorrent.

I think what makes IPFS interesting is that all files are like torrents and all folders all like torrents of torrents.

And since each torrent is a hash if the file underneath it, if 100 people individually add files or folders that contain identical chunks, then without explicitly doing anything the are so helping each other share those files.

[theamk]

In traditional torrents, the files are concatenated and only then divided into chunks. So if I take a existing torrent and add a single 16-byte file to the beginning, there is a good chance it will have no common hashes between new and old one.

Update: There is apparently "bittorrent V2" protocol [1][2], which allows file sharing. It is still not implemented in major clients, like libtorrent[3]

[1] http://bittorrent.org/beps/bep_0052.html

[2] https://news.ycombinator.com/item?id=14951728

[3] https://github.com/arvidn/libtorrent/issues/2197

[zcw100]

Not quite. They would need to use the same file and the same chunker. Two people can add the same identical file and share zero hashes. Files are broken down into chunks and those chunks are hashed I to a merkle tree.