When light travels from a less dense medium (like air) into a denser medium (like water or glass), it bends towards the normal.

Here's why:

* Speed of Light: Light travels slower in denser mediums. This change in speed causes the light to bend.

* Normal: The normal is a line perpendicular to the surface at the point where the light enters the new medium.

* Refraction: This bending of light is called refraction.

Think of it this way:

Imagine a car driving on a smooth, straight road (air). Then, it hits a patch of mud (water or glass). The car will slow down and turn slightly towards the normal line (the direction it would have continued if it had not encountered the mud).

Let me know if you'd like more explanation or examples!