L
LED
Light Emitting Diode.
Line level audio
Line level is a term used to describe the strength of an audio signal used to transmit analog sound information between audio components and sending to recording devices. It is used as it minimizes noise and distortion when processing, transferring or reproducing recorded sound.
Luminance
A signal that represents the scene brightness of the video signal information. The difference between luminance and brightness is that the latter is non-measurable and sensory. The color video picture information contains two components, luminance (brightness and contrast) and chrominance (hue and saturation).