Glossary: Last

Definition

A last is a wooden form that has a shape similar to that of a human foot. It is used by shoemakers in the manufacture and repair of shoes. Lasts typically come in pairs and have been made from various materials, including hardwoods,cast iron, and high-density plastics.

The last dictates the shoe size fractional fit (width/depth)  heel height and toe shape . Difering shoe styles require different types of lasts. For example  a shoe last is different to a sandal last and boot last . 

Source: Wikipedia