Genotypes are the genetic material responsible for your appearance. They are expressed in terms of alleles that determine your physical characteristics. Phenotypes are the actual characteristic that you see such as eye color and hair color.
A dominant gene is a gene that is expressed by a dominant allele and a recessive gene is a gene expressed by a recessive allele. The dominant gene will show the dominant phenotype, but a recessive gene will only show the recessive phenotype if you inherit both recessive genes and they are both present. This means that parents that both have brown eyes can have a blue-eyed child if they both carry the recessive gene for blue eyes and that gene is passed down to the offspring.
A dominant gene is a gene that is expressed by a dominant allele and a recessive gene is a gene expressed by a recessive allele. The dominant gene will show the dominant phenotype, but a recessive gene will only show the recessive phenotype if you inherit both recessive genes and they are both present. This means that parents that both have brown eyes can have a blue-eyed child if they both carry the recessive gene for blue eyes and that gene is passed down to the offspring.