Reflection gratings function as diffraction sources by altering the angle of the incident light beam, which causes the light to spread into various directions based on wavelength. A steel ruler can be used as a reflection grating due to its finely spaced edges that can diffract light, although it may not be as effective as specialized gratings. The discussion hints at the educational context, suggesting that the questions posed may stem from a homework assignment. Understanding the principles of diffraction and the role of angle in light behavior is crucial for applications in optics. Overall, the mechanics of reflection gratings are essential for manipulating light in various scientific and practical applications.