If we can get past the geek-speak barrier, you will be amazed how a little RGB working-space knowledge can improve the quality of your images.
First, you need to know what a working space is. Picture a triangle with red in one corner, green in another and blue in the third, with the colour gradually fading to white in the middle of the triangle.
Now imagine that the corners represent the reddest red, the bluest blue and the greenest green that the human eye can see. If you were to lay a grid over this triangle, you could then describe any colour in the rainbow by its x/y co-ordinates.
This is exactly what Photoshop does. If you have version 5.0 or greater, you can determine how much of this colour Photoshop will be allowed to work with. By drawing a triangle within that larger triangle, you define a working space.
You do not want to allow Photoshop to work with every colour because your scanner or digital camera will not be able to see all of those colours.
If you use a working space that is too big, colours will look unrealistically vibrant and pixels in the image will be very obvious and distinct. The problem will usually get worse if you try to make any changes to contrast, colour or brightness.
Hence, if you can find a working space that closely matches the colours that your scanner or camera is capable of seeing, it is possible to make a noticeable difference to the colour quality of your images.