mSATA SSD on Inspiron 17R SE(7720)

I've noticed that my laptop(Dell 7720) comes with a 32GB SSD.

I heard it is a "cache drive" but what is it for? What if I accidentally formated it?(And yes, I did wiped it out..)

How can I do a factory reset since I do not have a recovery disc and the warranty had already gone. Can I make a recovery disc on Dell 7737 and do a factory reset on Dell 7720? 

Thanks