The range of the scene in the photo taken by camera is shown in degrees. It is also called view angle.
It is important to determine the view angle of the lens when taking photos. This field angle is determined by the focal length of the lens and the field angle of the camera.
In the specifications of the lens, the range appears when the camera is set in the horizontal position is indicated by view angle of horizontal, vertical and diagonal. If only one thing is marked, it is called view angle of the diagonal.
Lens with a wide view angle is called a wide angle lens and lens with a narrow view angle is called a telephoto lens.