"Macintosh HD": is it Alias or Volume?

I am a new Mini owner and adjusting to Apple's way of doing things. In so doing I found the following anomaly. I removed all items, except "Macintosh HD", which was there after installation (10.13.3), from my desktop. When I click on Finder>Desktop there is nothing shown on my desktop. I put a file and an alias to that file on the desktop and both appear but not the "Macintosh HD". Get-info for the "Macintosh HD" lists it as a Volume. In Finder if I click on "Devices>my_user_name's Mac Mini" it lists Macintosh HD, Network and Remote_disc and lists the path as "my_user_names's Mac Mini". If I then click on "Macintosh HD" it lists the contents as Applications, Library, System and Users but now the path is "Macintosh HD". If I then click on Users it lists my_user_name and Shared and further clicking my_user_name gets to the default folders: Desktop ~ thru ~ Public but then clicking on Desktop still does not show "Macintosh HD". So my question is: If "Macintosh HD" is NOT an alias why is it shown on the Desktop and if I remove it am I removing the underlying folder and if it IS an alias why is its icon not listed as an alias? It all seems a bit messy and a trifle recursive. It seems to be kluge of a tree structure.

An explanation of Apple file system structure would be helpful.

P.S. This all came about because I wanted to see if I could hide everything but the menu-bar.