Disks are bundled into Pools, which are then divided into Spaces. Individual Spaces can then be doled out for complex storage scenarios. It's a pretty straightforward approach in the land of Storage Spaces, and actually works as advertised, I've found. (Image Source: TechNet)

You can't use a Storage Space as a boot volume... yet, of course. I am hoping that day will come, but for now, it's a mechanism for data storage sets only.

But just like RAID, you have a few options for how you can format your Storage Spaces to work. The three options you have include:

Mirror Space: This is the equivalent of a RAID-1, and my favorite Spaces flavor. Exact copies of data is mirrored across two or more drives, giving you the same redundancy that RAID-1 has offered for so long.  Needs at least 2 disks.
Parity Space: This is the equivalent of a RAID-5 array, using parity space to prevent disaster and recover data in the case of failed drives. I personally don't like this Space type as it has given me very poor write speeds in my testing (shown below). Needs at least 3 disks.
Simple Space: Just like a RAID-0, where you are striping data across multiple drives for raw speed but zero data redundancy. I would never use this production systems. This is good for temporary scratch spaces like video editing scenarios. One disk is all you need for this, but using two or more is really where this would shine.
As anyone who reads my work here knows, I'm not interested in marketing success stories. If I'm going to use Storage Spaces for my own company needs, and more importantly, for my clients, I need proof that this tech works.