During the Medieval period, art focused on religion and was commissioned by the church. Art depicted biblical themes and stories. During the Renaissance, art became more humanist and focused on realistic depictions of people and the natural world through techniques like linear perspective. Linear perspective used mathematical formulas to create the illusion of depth and distance on a flat surface, making paintings more lifelike. Famous Renaissance artists like Leonardo da Vinci began as apprentices, learning painting skills from masters, and helped develop the technique of linear perspective.