Difference Between Homozygous and Heterozygous

Individual organisms carrying two identical alleles (for example TT or tt) are homozygotes, and those with dissimilar alleles(for example Tt) are called heterozygotes.

Homozygous vs Heterozygous

Homozygous	Heterozygous
It is pure  for a trait and breeds true i.e., gives rise to similar homozygous individuals.	Heterozygous individual is seldom pure and produces offspring with different genotypes on selfing, eg., TT, Tt and tt on selfing of Tt individuals.
Both the alleles of a trait are similar, e.g., TT,tt	It carries dissimilar alleles, e.g., Tt
Homozygous individual can carry either dominant or recessive alleles but not both.	Heterozygous individual has both dominant and recessive alleles.
It produces one type of gametes.	It produces two types of gametes.
It does not show extra vigour.	The individual can show extra vigour called hybrid vigour or heterosis.