What is a terms dominant and resicieve mean?

In the context of genetics, "dominant" refers to an allele that expresses its trait even when only one copy is present, overshadowing the effect of a recessive allele. Conversely, a "recessive" allele requires two copies (one from each parent) to express its trait, as it is masked by the presence of a dominant allele. For example, in a trait governed by these alleles, if an individual has one dominant and one recessive allele, the dominant trait will be observed.