What is a .torrent file?
This is a small metadata file. Metadata here means that the file contains information about the data you want to download, not the data itself.
Your BitTorrent client needs the .torrent file to connect to the tracker (see below) and download the actual data you’re interested in.
What are seeds?
A seed is a client that has a complete copy of the data of a certain torrent. Once your BitTorrent client finishes downloading, it will remain open until you click the Finish button (or otherwise close it). This is known as being a seed or seeding.
more seeders=better download speed
What are leechers?
A leecher is a client that is currently downloading the data of a torrent. A leecher does not have the complete file, otherwise it would be called a seed.
more leechers = lesser speed of download