What is the difference between a zygote and an endosperm?

i)A zygote if formed due to the fusion of two gametes while endosperm is not from the fusion of two gametes.

ii)A zygote is of 2n condition while endosperm is of 3n condition

iii)A zygote later develops to a plant while endosperm provides nourisment to it.

iv)After fertilization it is a fact endosperm develops first then zygote so that the zygote gets the nourishment sufficiently.