What is the difference between a dominant and recessive allele?

 Dominant alleles are the alleles that give the phenotype, masking over the other phenotype while recessive alleles are the alleles that are suppressed by the dominant allele. A dominant allele produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent. For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent.