With zoom you can manipulate the distance between the optics in your lenses to bring distant objects closer.
It is not recommended to zoom while shooting because the lack of an identifiable point of view can feel very unnatural. If you want to approach a distant object it is preferable to cut directly into a long shot.
Shooting across many layers of atmosphere can affect the brightness and colors, and it’s harder to do using low end lenses.
Always remember that digital zoom (unlike optical) is merely enlarging the image and will add noise. Using a tripod or any improvised support is also highly recommended.