Another area where people get confused in lighting is the difference between hard/soft light and high/low contrast. Many people intuitively think that high contrast pictures are made with hard light and less contrast are made with soft light like so:
In fact contrast is the ratio between the brightness of shadow and brightness of light part whereas hard/loft light is about how sharp the shadow border is.
For instance, here is contrasted picture with soft light, see how the shadow gets gradually deeper on her face.
And hard light picture with uniform light field. Notice the shadow from her chin, shadow on the ear and boldness of textures in general. Compare it with picture #2.
This texture difference has a lot to do with this question and also leads us to our next topic about texture/color balance.