This is a monounsaturated fatty acid .
Saturated fatty acids are those where all the C atoms are bonded by single bonds.
When they are bonded by single bonds, each C has the maximum amount of H atoms it can bond to. It’s then saturated with H atoms.
When there are fatty acids with double bonds, then they are called unsaturated bonds as they don’t have the maximum number of H atoms.
The fatty acid in the question all the C atoms are bonded by single bonds except for one double bond , therefore it’s monounsaturated fatty acid