When the vanilla flower is pollinated it produces a pod with a bean inside.
Vanilla powder is pure, unadulterated vanilla bean made by grinding dried vanilla beans. This is the purest form of vanilla with the most vanilla flavour
Vanilla extract is made by washing and then soaking ground or chopped vanilla beans in a solution of ethyl alcohol and water. Often a blend of beans from different vanilla is used, but you can also find extract from just one kind, e.g. Madgascar. Vanilla extract can contain small amounts of sweetener.
Vanilla essence is often made using water, ethanol, propylene glycol, emulsifiers, and chemically produced flavours and colours. The vanilla taste is usually not as strong as in the extract.