A question from a beg. graphic designer about saturation and brightness?

Question:

A question from a beg. graphic designer about saturation and brightness?

I am trying to teach myself graphic design until I can save enough money for school... I am confused the def. of saturation and brightness in design and photography if saturation is how vivid or dull a color is and brightness is the amount of lightness of a color isn't it really the same thing for example a light blue coat has hi saturation of blue and alot of brightness why the difference of terms I am attempting to teach myself photoshop and this is confusing to me or do I have the concepts wrong, could someone example? thanks

Best Answer - Chosen by Asker: Look at it this way. Every picture has within it a range of white to black pixels, the greyscale. If you run the saturation slider down to nill that is what you see, the lightness or darkness of each pixel which gives a monochrome (single colour) image. As you run the slider up again the colour element begins to show. The mid point is usually the most accurate rendition of the original. As you go higher the colours become more intense. The picture does look brighter but that is only because the colour saturation is greater.
Taking the brightness slider down to nill you will just have a black image because this slider operates on every element of the pixels, not just the colour element but the greyscale element too. Increasing the brightness increases both colour and greyscale so at the maximum the image is white.
That is the difference. Saturation affects the colour element of the image, brightness affects the whole image.
Use both and observe the different effects. You will soon get the idea.