The film Rain Man explores the relationship between two brothers - Charlie, a self-absorbed businessman, and Raymond, who has autism and lives in a mental facility. The story follows them on a cross-country journey that helps Charlie better understand Raymond's condition. While Raymond struggles to communicate, over time their brotherly bond grows as Charlie learns to see from Raymond's perspective. The film highlights the challenges of caring for someone with autism but also the ability to overcome differences through love and understanding between family members.