Red is a primary color, you can't mix 2 to get red. Blue is primary, too, and so is yellow. You can mix any of the above colors to make another color. ie: red and yellow make orange. red and blue make purple. blue and yellow make green. yellow and green make light green. white and red make pink.
Difference between Optical Mouse and Laser Mouse. Key Difference: The optical mouse uses a light-emitting diode, while a laser mouse uses a laser in order to detect movement. A mouse is hardware that is required when trying to navigate on a desktop PC. However, many people these days also use a mouse on their laptops as it makes navigation easier.
An optical disk drive uses a laser to read and write data. A laser in this context means an electromagnetic wave with a very specific wavelength within or near the visible light spectrum. Different types of discs require different wavelengths.