Most of us are probably familiar with a graphical file manager, which represents the filesystem tree, as in Figure 2-1. Notice that the tree is usually shown upended, that is, with the root at the top and the various branches descending below.
Figure 2-1. Filesystem tree as shown by a graphical file manager
However, the command line has no pictures, so to navigate the filesystem tree, we need to think of it in a different way.
Imagine that the filesystem is a maze shaped like an upside-down tree and we are able to stand in the middle of it. At any given time, we are inside a single directory and we can see the files contained ...