The term "f/1.8-2.8" refers to the aperture range of a camera lens. The f-stop number indicates the size of the lens opening, with lower numbers allowing more light to enter. An aperture of f/1.8 is wider than f/2.8, making it ideal for low-light conditions and creating a shallow depth of field, which helps blur the background and emphasize the subject. This range is commonly found in zoom lenses and prime lenses, providing versatility for photographers. A lens with an aperture of f/1.8-2.8 can produce sharp images with good bokeh, making it suitable for various photography styles, including portrait and landscape photography.