Seed

A seed is someone who has completely downloaded a torrent, and leaves it in their client to let it upload to others. To be "seeding" a user does not have to be actively uploading the content to anyone (the leech) at that time, simply having the file in the torrent client where it is offered to anyone who wants to download it is enough to be considered seeding.

To be seeding the file the torrent client has to be running, and the torrent can't be stopped. If a user of a private tracker is seeding the file then they will start gaining seed points if the tracker has that feature.