Aperture settings refer to the size of the opening in a camera lens that allows light to enter. Measured in f-stops, a lower f-stop number (like f/2.8) means a larger opening, allowing more light and creating a shallow depth of field. This results in a blurred background, making the subject stand out. Conversely, a higher f-stop number (like f/16) indicates a smaller opening, letting in less light and increasing the depth of field. This keeps more of the scene in focus, which is ideal for landscape photography. Understanding aperture is essential for controlling exposure and achieving desired artistic effects.