How to tell if an extended lense can be added onto a camera?

So iv been looking at Nikon cameras and admit I'm confused. My think is I do a lot of nature and animal photography so I need to have an extended camera lense, so when looking for a camera how do i tell if it. Can have an added lense? I hope this makes sense. Also sorry for spelling and grammer mistakes i'm on my new phone and not used to it.

Digital SLR cameras use interchangeable lenses and here are two links that may help you:

The first lists all the available lenses for Nikon digital SLR cameras

The second shows how different focal length lenses "see"

With such a camera, you remove one lens from the camera and replace it with another.

The lenses you need for shooting animals (wildlife), you need to consider a telephoto lens that is at least 200 mm (300 mm or longer will produce the "reach" you need. Nature is such a general term, it can mean landscapes, macro closeups or wildlife. This can include super wide angle lenses and macro lenses in addition to telephoto lenses.

Now if your budget will not support the cost of a fully adjustable camera like a digital SLR ($450 for a Nikon D3200 with 18-55 mm lens) and a telephoto lens (about $400 to $600 depending upon the lens you choose), then the P&S camera that many of my birder friends like is the Nikon Coolpix P900 ($600) which has a super telephoto zoom lens. With it you do not have to change lenses, even if you could (the lens is permanently attached to the camera) See the third link

You mean telephoto lens? See a long explanation of lenses below.

http://keerok.wordpress.com/2014/12/17/what-is-the-best-lens/

If you have a camera with an interchangeable lens mount, you can replace the lens with a "longer" one. Nikon cameras that qualify are the dSLRs (D40, D90, D3300, D7200, D300, etc.) and the mirrorless (Nikon 1 series).

If you have a Nikon Coolpix, sorry. That camera has a permanently attached camera. You can't change it with a longer one.

DSLR cameras, and CSC cameras (called EVIL in USA) take interchangeable lenses, including telephoto zooms which can, if you have enough money, bring distant objects very close.

When you say you need an "extended lens" what do you actually mean?