Have you ever heard a designer or a printer ask you for a file in RGB or CYMK and it sounds like a foreign language? Here's a quick and easy explanation of what they mean and why to use them correctly.
RGB refers to the three primary colours, Red, Green and Blue. RGB colours use light to make their colours bright. If you mix them all together you would get pure white.
RGB is the colour profile used for digital screens and devices. Your screen mixes red, green, and blue light to produce the bright colours you see on your display. Websites, mobile apps, video, etc are in RGB.
CMYK is the standard colour profile for printing. Typically, your printer uses, Cyan, Magenta, Yellow and Black inks to print coloured images. When all colours are mixed together, a rich black is produced.
CMYK is used for printed materials. CMYK colours do not appear as bright as RGB (they are missing the added bonus of lighted screen). Brochures, business cards, posters, etc may be printed in CMYK.