In evolutionary biology, characters, in contrast to traits, are shared similarities, which are regarded as properties (structures or behaviors) in different organisms. They are treated as being heritable and homologous. Differences between homologous characters in different organisms are called character states or modes. A character differs from a character state in that it only specifies a property that is not observable rather being a hypothesis about a homology. Consequently, a character requires a comparison of different organisms as a single organism does not have characters, but only properties. In psychology, there is no real distinction made between character and trait.
See Constitution, Evolutionary biology, Homology, Mutant, Organism, Phylogenetic mapping, Trait