How do I access these 3 hidden volumes? The following image shows my Disk Utility window.

It says there are 5 volumes in total, but I can only access two: Macintosh HD and Macintosh HD - Data. Apparently one of them is a Virtual Machine as denoted by the VM. Another one of them is Recovery, but I do not know what this means exactly. The final volume is not mounted; it does not even mount after I click the Mount button.
Is there a way possibly through terminal or Recovery mode in where I can access them and determine if they are useful or not? I am running macOS Catalina on my 2015 iMac if that helps.
Thank you in advance!
A typical APFS volume under Catalina will have 5 partitions.

Macintosh HD: the read-only volume that stores the OS
Macintosh HD - Data: the 'normal' everyday volume where you save stuff to.
Preboot: a small amount of data used ... before booting.
Recovery: the Recovery volume that you boot to when holding Command R
VM: caches for virtual memory.

These are all essential, and you should not need to access them or do anything else with them.