What is the difference between homozygous and heterozygous allele combinations?

Homozygous means no alleles; heterozygous means one allele.

Homozygous means two different alleles; heterozygous means two identical alleles.

Homozygous means two identical alleles; heterozygous means two different alleles.

Homozygous means dominant alleles; heterozygous means recessive alleles.