Perspective has a large influence on the way an image looks. It is dependent on picture angle and focal length used. Perspective changes the way an object looks in size and distance to the camera.
When using a wide-angle lens the background appears to be very far away. When moving the main subject closer to the camera it will look larger and more dominant in the frame relative to the background, which will remain the same distance away. This phenomenon can be used effectively to focus extra attention on the main subject, though when carried to an extreme this can give an unrealistic view of the scene. This opening up of perspective with wide-angles is called exaggerated perspective. A view appears much wider than our eyes would normally see it.
Telephotos show the opposite effect. Because of their much narrower angle of view, objects appear to be much closer together than in real life. They compress perspective since objects in foreground and background appear to be more similar in size. When looking down a street through a telephoto, it will be difficult to guess distances between objects as they all appear to be at the same relative distance to the camera. This can be used to create the illusion that a street or a scene is bustling with people, or that buildings are stacked on top of another.