Can I sell Satoshi?

Excuse me, I'm a bit confused about something. Could you please clarify for me? I've been hearing about this cryptocurrency thing, and I understand that Satoshi is a part of it. But my question is, can I actually sell Satoshi? I mean, is it like a physical asset that I can trade for cash or other currencies? Or is it something more abstract that can't be sold in the traditional sense? I'm really interested in understanding how this all works, so I hope you can help me out here.