Torrentz is a play on word for torrents. Torrents are just simply bittorrent files and the use of the word Torrentz comes from the warez piracy scene on the net using Z at the end of the word to designate it as a illegal copy of copyrighted works. Other examples are appz, gamez. crackz and serialz.
The use of the word Torrentz is also further supported by the very popular Torrent Search engine called Torrentz
The Bittorrent protocol uses the file extension .torrent so bittorrent files are often just called torrent files which gets further changed to torrentz. This means that the term torrents is interchangeable with bitTorrents and both are the same thing.
Download torrentz from one of the public or membership torrent trackers and use one of the top two bittorrent clients.