Different lenses or lens settings can completely change the way your camera "sees" the world in front of you. Once you get familiar with the way things look with different lens settings, you can begin to make decisions about which setting will be best to create your image. The different lens settings are technically called the "focal length". Often you may hear it referred to as the "zoom setting" of your camera, but not all lenses are "zoom" lenses, but all lenses have a focal length.
Most of you will have a "zoom" lens for your camera, which allows you to change the focal length of your lens without changing to a different lens. Short focal lengths (or small numbers) are generally called "wide angle" lenses, while long focal length settings (large numbers) are called "telephoto" (like telescope).