If you shut down your torrent client (or your computer), you'll stop to seed. When you've completed the initial seeding, means distributed a full copy and there are other seeds, that doesn't do a harm to the torrent. It will be kept alive by the others.

If you haven't completed the initial upload and you shut down, the peers will exchange the parts they got, but can't complete the download.

If you know in advance that you can't run the computer long enough without a break (many people don't have their PC running 24/7, so that is normal), place at the bottom of the description an indication of your likely seeding times in UTC. That avoids complains

Thank @Popper! That cleared a lot of things up for me.

If you haven't completed the initial upload and you shut down, the peers will exchange the parts they got, but can't complete the download.

If you know in advance that you can't run the computer long enough without a break (many people don't have their PC running 24/7, so that is normal), place at the bottom of the description an indication of your likely seeding times in UTC. That avoids complains