I$\text{'}$m trying to summarize basic principles of reflection and refraction in optics; is the following accurate? In general, when light moves from one medium to another, both reflection and refraction typically occur simultaneously. The proportion of reflection versus refraction depends on a variety of factors, including the angle of incidence and the respective refractive indices. When light travels from a denser medium $($higher refractive index$)$ to a less dense medium $($lower refractive index$),$ there is a critical angle at which refraction does not occur at all. All the light reflects back into the denser medium$$this is total internal reflection. At normal incidence, there is no change in direction of the refracted light, but some light may still be reflected, depending on the refractive indices. And at Brewster$$s angle, the reflected light is completely polarized $($perpendicular to the plane of incidence$),$ but reflection and refraction still generally occur in this case, although no reflection will occur if the incident light is polarized to begin with $($and the electric field is oscillating in the plane of incidence$).$