Haplosufficient means- Single, Enough. When a single copy of a particular allele of a gene is sufficient to express it's phenotype. example: Tt = Tall : This phenotype is equal to Tall because the single dominant allele is enough to express the phenotype.

Haploinsufficient means - Single, Not enough. When a single copy of a particular allele of a gene is not enough to express its phenotype. example: Tt= tall. This phenotype is equal to Tall because your respective allele can not express itself.