Question : Problem: Why is my laptop hard drive in 2 partitions?

I was wondering, why is it that laptops very often come with the hard drive in 2 partitions.  My Sony Vaio is in 2 x 18 Gig partitions.  One has the OS the other is empty. why?

Cheers

Answer : Problem: Why is my laptop hard drive in 2 partitions?

I don't think it is common to have 2 partitions. Some feel it is safer to have data in the second partion should a recovery be necessary.