Definition
The opening in a camera lens through which light passes to reach the sensor, measured in f-stops (e.g., f/1.8, f/2.8, f/8). A wider aperture (lower f-number) lets in more light and creates a shallow depth of field with background blur (bokeh), popular for talking-head YouTube videos. A narrower aperture (higher f-number) keeps more of the frame in focus, useful for tutorials and screen recordings.