flash memory erasing - C

I saw this code:

EraseInitStruct.TypeErase   = 0x00000000;   //<-----equal to FLASH_TYPEERASE_PAGES
EraseInitStruct.Banks       = 0x00000001;   //<-----equal to FLASH_BANK_1
EraseInitStruct.Page        = 0x0000000F;   //<-----15 (0x08007800 - 0x08007FFF) (the 16th page)
EraseInitStruct.NbPages     = 0x00000001;   //<-----1

I understood this code deleting page 15 from flash storage. But i know in flash we can delete just blocks/sectors and not pages...

How this function work?

Thank you