multiple partitions

[Glenn Hudson]

Hi,

I am hoping someone might help me understand why Linux is usually setup
a certain way.

Most Linux PC have only one disk drive yet it is recommended that the
disk be partitioned into many pieces (home, root, var, swap). I thought
this kind of setup would cause excessive disk head movement. What is the
advantage of have root, home, var in seperate partitions and why isn't
disk head movement excessive?