First, look at each of the groups connected to the two carbon atoms in the double bond. Rank these groups by priority based on the atomic mass of the atom connected to the alkene carbon. If both of the heaviest groups are on the same side of the alkene, it is classified as (Z), which is zusammen, together in english. If they are on opposite sides, it is classified as (E), which is entgegen, against or opposite in english.