5.1 | Aperture and Depth of Field
5.2 | Shutter speed
5.3 | ISO
5.4 | The exposure triangle
5.5 | Histogram
5.6 | Bracketing
5.7 | White balance
The white balance determines the so-called colour temperature of an image. If the colours in an image are exactly as they are in reality, then it is correct white balance. If this is not the case you speak of 'colour cast' and the photo is often yellower/redder (warmer) or bluer (colder) than reality.
Below you can see the difference between certain Kelvin values. Move your mouse over the picture to see the difference.