Picasso changed art by showing the world that an artist does not always have an specific style, he can have several styles to make his pieces. For example Picasso, used different styles like cubism, painting in blue, modernism or the pink age. He show us that humans, just like artists, change with time and different experiences. That, every person and society acts and develops according to their life experiences and step by step their styles turn into what they are nowadays.
For expample, in his paint called "The woman with her arms crossed" he used his style called " Painting in blue" to express the tough life conditions in which the marginalized social class live in. And this is what Picasso saw and knew, so he wanted to express it by using this style in his pieces.