Contrast
The difference

From the camera it's a little flat |

Lift the contrast |

High contrast creates mood |

SIlhouette |
Contrast also adds drama and mood to a photo. Contrast is one of
the most important things to understand when taking photographs and
is best understood in terms of black and white when items of
different shades or colour are placed within the same frame they
contrast with each other.
If the subject of the photo happens to be pure white, to take an
extreme example, and the photographer places it in front of a black
background, then the result is known as high contrast. The obvious
result is that the eye will be drawn towards the contrasting white
subject. This is why silhouettes are so effective.
Look also at the levels in the histogram and lift the contrast
to create added drama and impact.