Answer:
First of all, the human body was painted or sculpted much more realistically than ever before. Medieval art, the type of art that preceded the Italian Renaissance, depicted the human body in simplified shapes, and lacked the concept of perspective.
Secondly, the human body and mind became the focus of art (perhaps except for architecture for obvious reasons). Some of the most famous works of art of the era depict people, for example, the paintings of the sixtine chapel by michelangelo, or the works of Da Vinci.