The answer is phenotypes.
Phenotype is the physical characteristics of an organism which are the result of interaction between genotype and environment. Genotype is the entire set of genes in the organism. Genes have alternative forms called alleles which can be the same or different at one locus. No matter if they are different, they have the same function but give different physical characteristics. Knowing the genotype can help predicting the phenotype. For example, if we know which genes determine the eye color and know someone's genotype, it is easy to predict if someone will have blue or brown eyes.