Nikon dslr focal lenses?

What's the difference between the 50mm and 35mm 1.8 lens? I know that focal lenses you zoom with your "feet" but is the mm the zoom distance on focal lens? If it is then the 35mm is wider? I'm using a 18-55mm so if mm is the zoom distance on focal lenses 35mm isn't really wide.

First, there's no such thing as a "focal lens." Lenses with a single focal length like those are called prime lenses.

Second, if you want to see the difference, why don't you just set your 18-55 zoom lens to 35mm and then set it to 50mm and look at the difference?

Yes, 35mm will give you a wider view than 50mm, but it's still not a very wide view. If you want a wide view, you'll need to look at a 12-24mm zoom lens or a 10-20mm zoom lens instead.

What you call focal lenses are actually lenses with a "fixed" focal length; in other words, they don't have a zoom ring on the lens and only have one fixed view, unlike zoom lenses which cover a variety of focal lengths (e.g. 18-55mm focal lengths).

You can take a look at the lens specifications to determine wideness as well. Just look for a specification called "angle of view" which will tell you how wide of an angle the lens takes in.

The 35mm and 50mm lenses are called "prime lenses" which is a fancy way of saying fixed focal length.

On a 35mm film camera or full-frame DSLR (D700, D3) a 50mm lens is considered a "normal" lens since its angle of view approximates that of the human eye. On a 1.5x cropped sensor DSLR (D40, D60, D90, D3000, D3100, D5000, D5100, D7000) a 50mm lens has the angle of view of a 75mm lens on a 35mm film camera or full-frame DSLR. So on a cropped sensor DSLR the 50mm focal length makes an acceptable portrait lens.

The 35mm focal length lens on a 1.5x cropped sensor DSLR has the angle of view of a 52.5mm focal length lens on a 35mm film camera or full-frame DSLR. So on cropped sensor DSLR the 35mm focal length would be considered a "normal" lens.

For portraits with a cropped sensor DSLR use the 50mm focal length.

For pictures that more closely approximate how the human eye saw the scene use the 35mm focal length.

Just remember that if you don't have a D90 or D7000 you must buy Nikon's AF-S lenses if you want them to auto focus.