Typically an aperture is used to form the beam being transmitted. This could be to direct communications waveforms or be related to sensor applications where it was important to locate something to a...
Aperture measures the amount of light that enters the camera and exposes the film. Aperture values correspond to the amount of available light and the desired shutter speed. Aperture also controls...
well aperture can mean like a hole or a gap or it can mean like the camra lens thing that opens and closes Aperture in the microscope- It is the hole that lets in light onto the stage from the mirror.