What is the umportance of the scene between walter and beneatha

They disagree about how mama use the insurance money she is about to receive. Beneatha tells Walter, "that money belongs to mama, walter, and it's for her to decide how she wants to use it". Walter believes Beneatha covets mama's money for medical school, while Walter wants to buy a liquor store with the money. It's also clear that Walter resents Beneatha.