Avant-garde represents a pushing of the boundaries of what is accepted as the norm within the cultural realm. It refers to people or works that are experimental or novel particularly with respect to art culture or politics. In this group, you do not strive to develop just yourself; you strive to develop art for the world: make a difference and change the world of art as we know it. Your work will be controversial. People will claim it not to be art at all, just like people claimed that impressionism was not art when it first came into being. Van Gogh sold no more than one painting during his lifetime, but he changed art forever.
Just to widen this group a bit (because really, there will be very few works that are avant-garde for the whole of art…), the label avant garde will also refer to works that are the avant-garde OF THEIR TYPE, i.e. works that are using common media in a very, very new way.
Other groups to consider: