I found a definition from, which seems to define impressionism perfectly:

An art movement and style of painting that started in France during the 1860’s. Impressionist artists tried to paint candid glimpses of their subjects showing the effects of sunlight on things at different times of day. The leaders of this movement were: Camille Pissarro (1830-1903), Edgar Degas (1834-1917), Claude Monet (1830-1903), and Pierre Renoir (1839-1906). Some of the early work of Paul Cézanne fits into this style, though his later work so transcends it that it belongs to another movement known as Post-Impressionism.

I think that my personal favorite impressionist work is a work entitled Absinthe, by Edgar Degas. In this work, we are presented with a very dismal picture of a woman and man sitting at a table in what appears to be some sort of a bar. The expression on the woman’s face is enough to tell a thousand stories. The colors are of a very dark value with high contrast between the figures and the background. This painting illustrates very clearly the psychedelic effects of the now illegal drink absinthe. To me, if a painting can truly capture an expression, and make you understand how that person must have been affected.