The idea of abstraction has changed the way we view the world through the medium of art. Abstract art is defined as art that has no reference to any figurative reality. In practice though, abstraction must surely start with an aspect of reality. Pablo Picasso famously said in 1935, "There is no abstract art: you must always start with something."
In general, it seems that artists see abstraction as a way of depicting the underlying essence of a subject, leading to the idea of abstract expressionism where the life energy and emotion of the artist is depicted in their art.
Abstract art has always polarised people. We either love it and see great meaning in the shapes, colours and textures, or we find it meaningless and chaotic. It is however, impossible to view abstract art and see the world in the same way as before.