Alcohol boils at a lower temperature than water. The essence of distillation is to heat the “wash” to a point where the alcohol vapourises, this vapour rises up the still and into the cooling plant where it is condensed into a liquid. 

Malt whisky is distilled twice in a traditional pot shaped copper still which resemble large kettles and and cooled in a copper coil or condenser which runs from the top of the “wash still” to the “spirit still”

The liquid in the spirit still is distilled again to produce a finer spirit passes through a spirit safe to ensure the integrity of the product and then barrelled. (Pictures 2, 3 and 4). Pot still distillation is a  batch process.