I have been looking more into what takes the most room on my HDD and I have come across the hiberfil.sys file that rates 12.8GB, which in my mind is huge. My question is this: What is the main function of this singular file and can it be removed without compromising the Sleep feature of the OS?

Thanks, Dylan

Hiberfil is the hibernation file.  If you do not use hibernation your can delete it.  The computer will still sleep.  To remove it simply type

powercfg /H in an elevated command prompt.  That toggles it on & off.  Once off you can delete the file