Definition - What does Presentation Layer mean? The presentation layer is layer 6 of the 7-layer Open Systems Interconnection (OSI) model. It is used to present data to the application layer (layer 7) in an accurate, well-defined and standardized format. The presentation layer is sometimes called the syntax layer.
As shown in the next figure, an object is seen as black if it absorbs all colors of white light. A white object reflects all colors of white light equally. If an object absorbs all colors but one, we see the color it does not absorb. The yellow strip in the following figure absorbs red, orange, green, blue, indigo and violet light. It reflects yellow light and we see it as yellow. The eye also uses complementary colors in color vision.
Ultraviolet light frequencies are above violet on the spectrum and are invisible to the human eye. What you see glowing under a black light, whether on a fluorescent poster or an invisible hand stamp or a newly washed white T-shirt, are phosphors.e'll also see why black lights make some objects glow but not others, and we'll look at some interesting black light applications. If you turn on a black light bulb in a dark room, what you can see from the bulb is a purplish glow. What you cannot see is the ultraviolet light that the bulb is also producing.