The talent pool is a place for candidates that might not fit the current role they applied for, but you would prefer to keep their application for future positions.
You can find the talent pool in the jobs section on the right of "Archived".
The talent pool will show up in the "Position" dropdown when copying/ moving candidates.
When you're ready to move a candidate out of the talent pool, you can do so by using the bulk actions functionality to move the candidate in the appropriate position.
For more information on copying/moving candidates, check out our article about copying and moving candidates.