What does the term ‘carrier’ refer to in genetics?

In genetics, the term "carrier" specifically refers to an individual who possesses one recessive allele for a certain trait but does not manifest the trait in their phenotype. This is due to the presence of a dominant allele that masks the expression of the recessive allele. For instance, if we consider a trait controlled by two alleles, dominant (A) and recessive (a), an individual with one dominant allele (A) and one recessive allele (a) would be classified as a carrier of the recessive trait. Consequently, this individual does not show the trait associated with the recessive allele; however, they still have the potential to pass the recessive allele to their offspring, who might express the trait if they inherit another recessive allele. Therefore, the definition of a carrier hinges on the presence of a recessive allele that remains unexpressed phenotypically.