inmstalling on several partitionas as opposed to one

Ive noticed with opensuse it defaults to installing on seperate partitions where a lot of other distros just install on one single one.
Why is this and is there any advantage to using one method over another?

There must always be two partition: one for Swap and one root partition. But openSUSE offers you by default to use a separate partition for /home. This has the advantage that you can (re)install the system without touching the users files. This works of course only when you let not format the /home partition during that (re)install ;).