windowscentral[.]com/how-manage-storage-devices-windows-11
*To me* it's easier to manage hard disks/SSDs etc. using 3rd party apps like AOMEI's Partition Assistant &/or NIUBI Partition Editor Pro -- Much thanks to both companies for offering their software on GOTD. With excellent apps like those 2 it's easy to forget that you can do many of the same things using Windows builtin tools -- the linked article walks you through how to use them.
One thing the article doesn't touch on is Virtual Hard Disks [VHDs]. A VHD is a single file that when mounted or attached acts as if it was a separate, physical hard disk. Disk / partition image backup software uses VHDs to store backup archives -- they clone one or more partitions to a VHD. Some encryption software can create an encrypted VHD, same as you can encrypt a hard disk partition, using that as a sort of bucket to store files. Since Win7 you can boot to a VHD, though it's not something that's terribly popular so there's not a lot of support available. Using that you could for example upgrade Win10 to 11, restore an image backup of your old Win10 system partition to a VHD, set Windows boot loader to show a menu with both Win11 & your old Win10 [on the VHD], and have the option to continue using your old software in case you ran into problems or until you got used to Win11 etc. And when you're done with that old copy of Win10 for good, delete the VHD & remove Win10 from the boot menu. You could always do the same thing, creating another disk partition for your old copy of Windows, but you might find it easier with a VHD vs. creating & then deleting a partition. You can also use VHDs as a temporary replacement for a physical drive partition, e.g., restore a sector by sector image backup, then run file recovery software on the VHD while you continue to use your PC.
At any rate, VHDs are handy enough that Microsoft brought the needed tools into Settings for Win11 -- in Win10 you still need to use Computer Management -> Disk Management. There are several *flavors* of VHDs, with image backup apps often using their own proprietary format, virtual machine host software using their own, e.g., VirtualBox uses .vdi etc. For Windows VHD formats here are the basics:
elevenforum[.]com/t/create-vhd-or-vhdx-file-in-windows-11.19203/
learn.microsoft[.]com/en-us/windows-server/storage/disk-management/manage-virtual-hard-disks
Before you dive into VHDs however, it's important to know that there are two types, fixed size and dynamically expanding -- you choose the type of VHD when you create it. A fixed size VHD allocates the full size of the VHD as soon as you create it, so a 5GB VHD will result in a file that's roughly 5GB. Because all the disk space is already allocated, writing to the VHD is faster than writing to a dynamically expanding VHD. A 100GB dynamically expanding VHD OTOH will only take up a few MB, growing only as it needs to accommodate whatever files you store there. But, writing files to this VHD will take slightly longer, because it first has to grow large enough for the files to fit. Another *maybe* catch is that a dynamically expanding VHD will grow, but never shrink on its own. If you wind up with a bunch of free space taking up room in that VHD, and you want to shrink it to take up less space, you have to manually shrink or compact it.
learn.microsoft[.]com/en-us/powershell/module/hyper-v/optimize-vhd?view=windowsserver2022-ps
nakivo[.]com/blog/shrink-compact-virtual-hard-disks-hyper-v/
learn.microsoft[.]com/en-us/windows-server/administration/windows-commands/compact-vdisk