All amines have a nitrogen at their core. This amine can be a primary amine (R-NH2) where the nitrogen is bound to 1 carbon atom and 2 hydrogen atoms. It can be a secondary amine (R-(NH)-R) where the nitrogen is bound to two different carbon atoms and 1 hydrogen atom. It can also be a tertiary amine (R-(NR)-R) where the nitrogen atom is bound to three different carbon atoms. But all amines contain a nitrogen atom that is not a part of an aromatic system (that is to say that the nitrogen is not part of a double bond).