Lens, 18-105 mm? Needing some professional

I'm new into Dslr cameras.
So I wanted to know should I buy a 18-105 mm lens for my Nikon d3100, and how can it be used?
Why it is different than 15-55mm, which is the difference?

It should be obvious that the 18-105 mm has a longer reach than the 18-55 mm. For that reason, may people buy the 18-200 mm lens.

Here is a link that will show you what different focal length lenses "see" in relationship to others.

http://www.tamron-usa.com/...arison.php

This is NOT an endorsement of Tamron lenses, just a tool to help you understand the use of various lenses

15-55mm is a good general purpose lens. It will take you from photographing panoramic scenes and up into portrait photography. The 18-105mm is moving further into the portrait end of the lens world and possibly some sports and even wildlife.
I'd probably go for the 18-105mm. But I'm an amateur not a professional

I wouldn't buy the 18-105, as it covers a lot of the range that you already have. If you do buy it, you won't need the 18-55 any more.

My suggestion would be to get either the 55-200VR or the 55-300VR, both of which are great lenses if you want more reach.