Summary of the hidden folders and files you’re most likely to encounter at the top level of a volume, and at the top level of your Home folder.
volume
In recent years, most Mac users have stopped partitioning drives into volumes. In High Sierra, you will probably want to use volumes again. Lots.
Being a hybrid, naming disks and volumes can get complex in OS X. This article demystifies them.
The Eclectic Light Company 