The physical appearance of a trait is called the phenotype, while the genetic composition is called the genotype.

Here's a simple breakdown:

* Phenotype: What you see (e.g., brown eyes, tall height).

* Genotype: The underlying genes that determine the phenotype (e.g., the specific combination of eye color genes, the genes for height).

For example, a person with brown eyes could have a genotype of BB (two dominant brown eye alleles) or Bb (one dominant brown eye allele and one recessive blue eye allele). Both genotypes result in the same brown eye phenotype.