Loops can be in different positions - originals and copies
A loop that you build yourself becomes an original loop. An original loop can be published by you in any library, as you "own" it yourself.
There are four scenarios in Loops where copies of loops are made. That is:
1. When you push the button Remix loop in a loop in the library.
2. When you Start a loop, either from the library, or from My Loops.
3. When you have rebuilt a loop that you started and choose to Copy loop.
4. When you publish a loop in a library.
A copy taken from the library by Remixing the loop ends up under My loops and can be rebuilt by you and started by you, but not published in the common library. That is because you don't "own" it. But if you have rebuilt it and like to show it to your colleagues you can publish it in your schools own library.
A copy that is made when you start a loop ends up at the Start page. You can rebuild the loop there if you like, even after you started it with your students. If you rebuild it quite a lot, you might want to save a new copy of the loop. Then you chose to Copy loop, and a copy will end up under My loops.
If you owned the original of the loop, the copy will also be an original. This only matters if you like to publish it in the common library, because that would then be possible.
The copy that is made when you publish a loop in the library is different from the other ones. Even if it's a copy it's still connected to the original. The reason for that is that you should be able to update and adjust things in the original loop and then republish it to get the changes over to the loop already published in the library.
It can be a bit confusing that you can't push over updates from the original loop to the loops you have started, as you can with the ones you have published, so you have to be aware of that difference.