Final answer:
A ray of light bending towards the normal when entering a second medium signifies that the second medium has a higher index of refraction, indicating it is denser and that light travels slower in it.
Step-by-step explanation:
When a ray of light moves towards the normal upon entering a second medium, it indicates that the second medium has a higher index of refraction than the first medium. This bending towards the normal is a result of refraction, which occurs due to a decrease in the speed of light as it enters the denser medium. The Law of Refraction, also known as Snell's Law, mathematically describes this relationship between the angle of incidence, the angle of refraction, and the indices of refraction of the media involved.