White Balance and Color Temperature

Color temperature is a characteristic of light important to photography. It is a measurement in degrees Kelvin indicating the hue of a specific type of light source. Low color temperature implies warmer light (yellows and reds) while higher color temperatures impllies (more blue) light. Different lights give off different temperatures. White balance is telling your camera that a certain color is white. Even if the light appears blue, you're saying "hey, that's white not blue." The human eye views many shades of white, as white. But the camera can not decipher what is white if it has a different hue to it. So, there is a setting on the camera in which you can point your camera to the object in the light you want to be viewed as white.
Here are some common color temperature, measured in Kelvin.

1500 K Candlelight
2680 K 40 W incandescent lamp
3000 K 200 W incandescent lamp
3200 K Sunrise/sunset
3400 K Tungsten lamp
3400 K 1 hour from dusk/dawn
5000-4500 K Xenon lamp/light arc
5500 K Sunny daylight around noon
5500-5600 K Electronic photo flash
6500-7500 K Overcast sky
9000-12000 K Blue sky

Here is an example of unrealistic white balance, and the same photo with the white balance correct on the camera:

1. Incorrect.

2. Correct.

I hope you now understand white balance and color temperature.