Direct applicability relates to a stage where the EU law needs to be involve in the domestic legislations of the law in order to implement it to its system.
EU regulations are directly applicable, meaning there is no need to for an additional act in the local state parliament in order to include it in the law system of that country.
Although, EU directives are not directly applicable, since they require the member state to do something about it, so they also need to enact it into the national law.
Direct effect:
Direct effect refers to whether individuals can rely on the EU law in domestic courts, meaning one apply to the national court in a case regarding this law after the law was enacted in the EU level. There