How to check the storage details of my computer

I bought a new computer with the storage: Dual: 1 TB*2 / 2TB RAID0 (2*1 TB), but I can only find a "C: " with 1.83 TB in my computer. Shouldn't there be two drives? Or, what's the difference between Dual and Single of storage?

I'm a little confused about the hardware techniques of computer, grateful for helping me!