This lecture covers the properties of the Riemann integral, including its definition, boundedness, and characterization of measurable sets. It discusses the Riemann integral on any set, the geometric interpretation of the integral, and the concept of Jordan-measurable sets. The instructor explains the conditions for a set to be Jordan-measurable and the implications of being Jordan-measurable. The lecture also delves into the characterization of measurable sets and the significance of neglectable sets in integration theory.