A Telephoto lens has a focal length that is longer than 55mm but typically starts out at 70mm. A short telephoto lens, such as a 70mm, will allow you to take excellent portraits. A longer lens, such as a 210mm or 300mm, will let you see further so you can photograph boats, planes, or wild animals from a distance. There are two important limitations to remember when using telephoto lenses. They tend to shorten your depth of focus and they are more susceptible to camera shake.
Camera shake is a result of noticeable movement of the camera that is seen on the film.
It generally appears when the shutter speed is set too low but can usually be compensated for. Wide-Angle lenses widen the angle of view from the camera. These lenses allow you to expand the scope of your photograph without having to move back in order to get everything you want to see in the frame. They are very useful when taking photographs inside when you may not be able to back up or with landscapes where your positioning will not significantly alter the angle of your photograph. Anything that is close to the lens will appear disproportionately large in comparison to the rest of the picture.