Zooming serves for enlarging or reducing of the drawing area. By using the Zoom command the drawing area can be larger than the client area. It enables you to browse your drawing more in detail by scrolling through it.
Because in the zoom mode you always see only a part of the drawing, you can use the Aerial View to still see the entire drawing and to navigate in it.
Notice: Creating of large drawing area is limited by Windows limitations and by your system configuration. Generally the more colors you use in video configuration, the more memory you need for creating a drawing area with certain size. Note that by creating of very large bitmaps you may easily overload your system if it uses virtual memory.