This page explains the semantics of removing, recycling, and deleting with regards to solvers, benchmarks, and jobs.
Primitives (solvers, benchmarks, and jobs) on StarExec exist independently from the spaces they are associated with. In other words, primitives can be both added to and removed from spaces without having any affect on the underlying primitive. On StarExec, to "remove" a primitive simply means to disassociate a primitive with one or more spaces that it is currently associated with.
Notably, this means that removing a solver, benchmark, or job from a space does not delete it. Removing and deleting are completely separate operations. Even if a primitive has no remaining space associations, that primitive still exists on StarExec. Such "orphaned" solvers and benchmarks can still be viewed, downloaded, and used in jobs. Importantly, they also still count against your disk quota! To remove the primitive from your quota, you need to delete it permanently, which is discussed below.
Because the normal method of adding primitives to new spaces is to drag them from a space they currently exist in to a new space, it is more challenging to place orphaned primitives into spaces. Orphaned primitives can still be added to spaces by uploading a space XML document to create new spaces that contain the orphaned primitive. We intend to make it possible to associate orphaned primitives with existing spaces in the near future.
The recycling mechanism exists to safeguard against accidental deletion of primitives. When a primitive has been recycled, it is no longer available to be used in jobs, but it does still exist on disk. This means you can still elect to restore primitives that have been recycled.
Because recycled primitives still exist on disk, they do still count against your disk quota! To delete primitives that have been recycled, you can use the recycle bin page. This page can be accessed by clicking the trashcan icon in the space explorer or by clicking the "manage recycle bin" button on your profile page. That page also allows you to restore primitives, which means removing them from the recycle bin and allowing them to be used normally.
When you drag a primitive to the recycle bin and click "recycle," the primitive is also removed from the current space. This is for convenience, since users frequently want to remove and recycle primitives at the same time. However, it is important to remember that removing and recycling are still different operations!
The recycling mechanism currently exists only for solvers and benchmarks. Jobs cannot be recycled. If they are deleted, they are gone permanently!
To "delete" a primitive has the expected effect-- it permanently removes that primitive on disk. Deleted primitives will no longer count against your disk quota, but they cannot be restored in any way.
Even when a primitive is deleted, it is not removed from spaces! Again, deleting and removing are completely separate processes. Instead, primitives that have been deleted will be marked (deleted) in their spaces, and it is up to the members of that space to remove the deleted primitives. This allows you to see explicitly that a primitive in one of your spaces has been deleted, rather than having the primitive vanish silently from the space.