Hi vuvankhanhdhhh welcome to Sevenforums,
I believe you are talking about a VPN (Virtual Private Network)
To start you off, here is some reading material about VPN's:
HowStuffWorks "How VPNs Work"
Couple of things to note:
If your torrent client is maxing out your bandwidth then a VPN won't help. A network connection is only as fast as the slowest link in the chain, and if that's your internet connection, then you will see no benefits.
If however your torrent speeds are slow because of Traffic shaping (the policy of ISP's giving certain traffic, such as web browsing and VOIP priority over others, such as p2p) then a VPN will almost certainly help, as the connection is encrypted your ISP can't tell that you are torrenting.
There are many VPN providors out there, although it has to be said, the best one's aren't free. Two that I would recommend, that I personally have used in the past are Its Hidden and CyberGhost VPN, both have a free product with low usage caps and no speed guarantee's, but they can at least give you an idea if they will help. Full setup instructions are on the site:
ItsHidden:
Home
Cyberghost (german site translated into english so may read a bit weirdly):
Surf anonymously - Download now and use for free | CyberGhost VPN