Which of them can be deleted without danger for the system and its performance. And how to delete?
Would not recommend to delete any of this partitions.
The one partition contains the necessary files which are used in order to repair the OS in case something would be wrong with Windows OS.
The second hidden partition contains the HDD Recovery which allows you to reinstall the OS from HDD without the usage of Recovery disks.
So both are important files.
But you should definitely create a Recover disk (recover flash memory)
This will allow you to set the notebook back to factory settings if something would go wrong with the HDD or the partitions.