What is Alpha Channel?
The alpha channel is a color component that represents the degree of transparency (or opacity) of a color (that is, the red, green, and blue channels). It is used to determine how a pixel will be rendered when mixed with another pixel.
The alpha channel controls the transparency or opacity of a color. Its value can be represented as a real value, as a percentage, or as an integer: full transparency is 0.0, 0%, or 0, while full opacity is 1.0, 100%, or 255.
When one color (source) is mixed with another color (background), e.g. For example, when an image is superimposed on another image, the alpha value of the source color is used to determine the resulting color. If the alpha value is opaque, the source color overrides the target color. When it is transparent, the source color is invisible so the background color can show through. If the value is in between, the resulting color will have a different degree of transparency / opacity, creating a translucent effect.
The alpha channel is mainly used in alpha blending and alpha compositing.