1. If the path name starts with a slash, the path starts at the root directory.
2. A path name can be either one name or a list of names separated by slashes.
The last name on the list is the name of the file requested. All names preceding
the file’s name must be directory names.
3. Using two periods (..) in a path name will move you upward in the hierarchy
(closer to the root). This is the only way to go up the hierarchy; all other path
names go down the tree.