Sat­u­rated fatty acids: A fatty acid is sat­u­rated if a hy­dro­gen atom ac­cu­mu­lates on each free bond or "arm".

Mo­noun­sat­u­rated fatty acids: Where not all bonds are sat­u­rated with hy­dro­gen atoms, the neigh­bour­ing, free "arms" form a dou­ble bond. A mo­noun­sat­u­rated fatty acid is formed.

Polyun­sat­u­rated fatty acids: If there are sev­eral dou­ble bonds, we can speak of polyun­sat­u­rated acids. 

Un­sat­u­rated fatty acids are very healthy. Be­cause they are un­sat­u­rated, so still have free places, they can still form new chem­i­cal com­pounds. The body can use un­sat­u­rated fatty acids to cre­ate other or­ganic sub­stances, such as bind­ing free rad­i­cals and mak­ing them harm­less for the body in the process.

Fur­ther In­for­ma­tion

• Ar­ti­cle "Veg­etable oils: Un­sat­u­rated fatty acids keep the heart and body healthy"