i'm not really sure myself... but from what i've heard so far, it seems that the local ports are only for your computer, and the people on your LAN (Local Area Network).

This means you won't upload to people, and even if you do upload it will be very slow because your settings are limiting the kind of IP addresses that can access through those ports. This also means you will download pretty slowly on the Torrent network, because the Torrent network has an anti-leeching system. The faster you upload, the faster you will download.

You should allow some remote ports so that ppl can access your media from a remote location.

Or so.. this is what i gather? I don't use whatever torrent system you're using, so the meanings could be different. It could mean a different thing in a different context.