why not only one datasheet for STM microcontrollers

I know it's not a coding question , but I am struggling with something around my head for a little bit, for example stm32f446re : why it doesn't have only one datasheet , why so many datasheet for only one microcontroller , also my question is : how could I get all different possible datasheets for a specific microcontroller like stm32f446r4 Nucleo because I searched a lot but my instructor told me that there is about 6 different datasheets for stm32f446re , but what I could find is only 2 datasheets ?

Traditionally, documentation for microcontrollers goes like this:

• Data sheet = information for the hardware designers.
• Reference/User's Manual = information for the software designers.
• A separate core manual regarding the CPU Instruction Set Architecture (ISA) and assembler language, also for software designers.
• Application notes = additional information about either hw or sw.
• Errata. List of known hardware bugs. Always skim through it!

Please note that "Nucleo" etc isn't a microcontroller but a specific evaluation board. It will have additional information about that specific board.