Basically,Port Forwarding is that you can set your router to let internet users access your computer that behind your router.You router have a public ip and your computer just have a private ip.Internet users can just directly access your router,but not your computer.So if you are using utorrent or others P2P software and if you want get a high download speed,you must let internet users can directly access your computer.Then you must set your router and add port mapping.Often you must login into your router s administrator page and manually add port mapping. If you download movie or file from internet using azureus,utorrent or BitComet and want to a very high download speed,you must know how to operate your router to add or delete port mappings.-Basically, Port Forwarding is that you can set your router to let internet users access your computer that behind your router.You router have a public ip and your computer just have a private ip.Internet users can just directly access your router, but not your computer.So if you are using utorrent or others P2P software and if you want get a high download speed, you must let internet users can directly access your computer.Then you must set your router and add port mapping.Often you must login into your router' s administrator page and manually add port mapping. If you download movie or file from internet using azureus, utorrent or BitComet and want to a very high download speed, you must know how to operate your router to add or delete port mappings.