Red, Green, and Blue, or RGB, are the three basic colors of light and are frequently employed in gadgets like monitors and cell phones. The acronym CMYK stands for Cyan, Magenta, Yellow, and Black, which when combined produce the color black.
Since you will see your artwork differently in CMYK mode than in RGB mode, you must make sure that your artwork is done in CMYK to guarantee that it has the precise effect that you need.