A style created by Picasso and later to be copied by many others, Cubism shows everyday objects and people as if they were viewed from multiple sides at once.
You could say this was the 3D of the 1910s!
Modern Art is defined as art produced after the late 1860s that rejected the norms that everyone else liked to follow. It's thought of as a radical style, and included expressionism, impressionism, and cubism.
As an example, here's The Scream by Edvard Munch.