How can I tell if its a Partition or another drive?
Go into the BIOS (Usually F2 or Delete during startup). It should show what physical drives you have attached to your system.
There are also various utilities that can differentiate physical drives from partitions.
It's good to check, but I seriously can't imagine it's NOT a partition. The only laptops I've seen with 2 physical drives in them are ones that the owner went well out of their way to make it happen. Like, they removed the DVD drive to put another hard drive in.
I'd be shocked if the OP managed to buy a laptop with 2 hard drives without knowing it.