SSD's are special Hard drives which are based on flash memory (like the cards used in your digital camera) technology so that they don't have moving parts. Traditional Hard Drives use spinning metal platters and with moveable heads. Some of the early netbooks come with SSD's, but they were ridiculously small. Remember the original eeePC's with like 8GB hard drives?
Not sure if any of the current generation have large SSD's, but what you'll find is that they don't come in traditional hard drive capacities. They are often in multiples of 64, so 64GB, 128GB, 256GB and so on. So without digging up more detailed specs, I'd be guessing that the 250GB drive is a traditional hard drive and not SSD based on its capacity and the price range of the computer.
I'd also agree to avoid buying machine from place like Wal-Mart. I prefer going to a specialised computer or at least electronics dealer. This way if there are any questions or issues, you have a tech orientated person to speak to for help at the store and not just a retail sales person who happens to work in the electronics section