What is a "salon" ? This French-origin word has different meanings. The first would be the definition of an elegant living room. The second is "a fashionable assemblage of notables (as literary figures, artists, or statesmen) held by custom at the home of a prominent person." And here is an example of the third meaning of a Salon with a capitalized S : an annual exhibition of works of art. For instance the Paris Salon was where the eighteenth and nineteen century artists displayed their works to the public.
The Royal Academy of Art, established in 1648 by the Sun King, was the most significant professional art society in France. This school held annual exhibitions where artists could display their works of art and wait for the critics reviews! It provided the chance for young artists to be promoted and to make connection with patrons who could help them move out of the "starving artist category."
From the late eighteenth century this institution had a real monopoly on how the public defined good taste and on official patronage of the artists who exhibited at the Salon.
In the 1850's, new movements appeared and undercut the influence of the Royal Academy. They would later be seen as avant-garde movements. The Realists represented by Gustave Courbet, Jean-François Millet, and Édouard Manet was one of these movements. In the late nineteenth century, there appeared the most famous avant-garde movement : Impressionism. The first Impressionist exhibition was held in Paris in 1874, at 35 boulevard des Capucines, the former studios of the renowned French photographer Nadar.
By the end of the nineteenth century and the first decade of the twentieth, the Royal Academy's influence was gone and new Salons appeared, showing the works of modernist artists like Henri Matisse and André Derain.