Minimalist work focuses attention without distraction on the straightforward reality of the object, the relation of the object to the space in which it is seen, the relation of the viewer to this experience.
Michael Craig Martin 1988
Minimal art uses single forms or units, apparent simplicity, industrial materials and techniques and shapes that refer only to themselves. Minimal works are objects in their own right. They do not represent a landscape or figure or any traditional subject matter in art. They do not describe experience but are objects that generate new experiences for the spectator.
When we go to an art gallery we expect to see 'art' which is made from special materials, transformed by an artist into an object of beauty or wonder. With sculpture we expect works made from marble, bronze or clay  carved, cast or modelled, the result of a special talent and techniques gained through years of skilful training. The artist in this way ensures that the 'art' object is unique, has value and its own identity. An 'art' object by this argument is something that no-one but the artist can make. We ask, 'can art be excellent if anyone can do it?'
Minimal art continues to shock or to put it another way, still represents much that is difficult to understand in modern art. The materials used are commonplace, easily purchased off the shelf or normally found in manufacturing industries.