Phenotype is an organism's observable properties that are the result of the interaction of the organism's genotype and the environment. Observable properties include things such as eye color, height and hair color.
Phenotype is derived from the Greek words phainein, which means to show, and typos, meaning type. Different environments result in different influences of inherited traits and can lead to a different expression of similar genotypes. For example, height is affected by how much food is available to an organism.
Because of environmental changes and differences, the phenotype of a person can change throughout his or her life. Some possible variations of characteristics are never even exhibited in the phenotype because the genes are recessive or inhibited.