When a Trash folder is present in your top-level workspace, any items that are deleted from your workspace are automatically moved to the Trash.
If you accidentally delete an item, you can go into your Trash and restore the select item(s) by checking the box next to them and clicking on the Restore button.
If there is no Trash folder present in your top-level workspace, then a deleted item is permanently removed from the system.
All items in Trash still account towards your usage, if you are running low on space, ensure that you clear out any unwanted items in your Trash.