Although both Joe and Sarah are registered as users on their local UNIX system, they belong to different departments; Joe is a postgrad student in artificial intelligence while Sarah is Head of the Math Department. Their respective home directories might be:
/(root)
|
|
----------------------
| |
/tmp /home
| |
---------------- ... ----
| | |
/ai /biol /math
| |
---------- ---------------
| |
/joe /staff
|
------------------
|
/sarah
The full pathname to Joe's home directory is /home/ai/joe - that to Sarah's is /home/math/staff/sarah.