The edges are roughed and a hot glue strip is applied. Then the cover is added. Perfect bound books lie flat. Perfect binding is economical. This is hardback.
Case binding is expensive and a more intricate process than other binding.
It is appropriate for presentation copies and assured bestsellers. Many authors choose to case bind a few hundred copies. It is basically spiral binding or rivet binding. It is acceptable for the officeplace but not the commercial book market. Finishing Finishing is the catch-all process of book printing.