WOW! I bought 3800Sat right now

and price rised up 4600
i keep seeing you guys talk about buying SAT (satoshi) what the hell does that mean ;/ ? i tried looking up satoshi and how it converts to a calculation but i cant seem to find a clear answer on it.
Satoshi is the smallest unit for measuring btc.
SIGT at 0.00004640 btc is equivalent to 4640 satoshi.