A torrent file contains the URLs of multiple trackers and integrity metadata about all the pieces. It can also contain additional metadata defined in extensions to the BitTorrent specification.
Torrents are good for users because they can download any expensive and overprice software easily(e.g photoshop).The torrent users should be thankful to software engineers who crack high quality software applications by their reverse enginnering skills.They users can also download songs, mostly movies , ebooks etc.
But it is not good for software producing companies because because they spent too much time on research and development of software and at the end they are not rewarded well.
It has also affected the business of optical disc sellers ,any game song album and movie is easily download able by torrents.Song albums and movies are available in pirate version before release and film business is affected(that’s good).
The speed of the downloading depends on two things; the number of other users sharing the file and the number of other users downloading this same file.
Here are some of the popular torrent websites .