A device colour space describes the range of all colours that a camera can pick up, a printer can print, or a monitor can display. An editing space, on the other hand, is grey balanced colours with equal amounts of Red, Green, and Blue appear neutral. Editing spaces also involve changes of lightness, hue, or saturation and are applied equally to all the colors in the image.
What a colour space contains - Basically imagine a box that contains all different colours, the further away from the centre of the box, the colours become more saturated, etc. red towards one corner, Blue towards another, Green towards the third and a purple colour for the fourth. A Cyan, Magenta, Yellow colour space works the same way, except that the primary colours are CMY rather than RGB. In general, you want to use colour spaces that are as large as is practical.
YUV - YUV colour space is a bit unusual. The Y component determines
the brightness of the color (referred to as luminance or luma), while the U and
V components determine the color itself. Y ranges from 0 to 1 (or
0 to 255 in digital formats), while U and V range from -0.5 to 0.5 (or -128 to
127 in signed digital form, or 0 to 255 in unsigned form).
One neat aspect of YUV is that you can throw out the U and V
components and get a grey-scale image. Since the human eye is more responsive
to brightness than it is to color, many lossy image compression formats throw
away half or more of the samples in the chroma channels to reduce the amount of
data to deal with, without severely destroying the image quality.
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