Originally Posted by BlackMystic
What does 300 dpi mean?
72 dpi is not only for computer screens, it's the same resolution for every screen like FULLHD TVs, digital cameras, cellphones, smartphones and more. DPI resolution it's completly diferent at the size resolution of your screen. If you will work in this resolution (assuming your work will be displayed on a screen) you have to work on the color model RGB (Red, Green and Blue) this colors light are added together in various ways to reproduce a broad array of colors.
But, if you will work on a 300 dpi or higher document it's because you will print it. In this case you have to work on CMYK color model (Cyan, Magenta, Yellow and Key -A.K.A. blacK-). The CMYK model works by partially or entirely masking colors on a lighter, usually white background (the paper on your printer). The ink reduces the light that would otherwise be reflected. Such a model is called subtractive because inks "subtract" brightness from white.
And once again, sorry for my bad english.