Ok kool, so if I wanted a good lens for like travel photography in the future, then the $1000 ones are overkill? Or the cheap ones will do the job as well ?
The lenses that cost the most money (generally) are the ones with the biggest apertures (the smaller the number).
So (f = aperture), a lens that can open up to f/1.4 is a bigger aperture (the hole opens bigger in the lens to allow more light to go through) than a lens that is open to...say f/11.
When you have a lens that costs $2,000...like the Nikon 70-200mm f/2.8...what that means is that it doesn't matter what focal length you're zoomed to (70mm or 200mm), you can still have an aperture of 2.8. What this does is it allows more light to reach the censor...so the shutter doesn't have to be open as long...and thus avoiding camera shake and blur. It also has the added benefit of giving you a shallow depth of field...which is a nice way of saying "bokeh" ...or "that nice blur around the photo".
Making a lens like that costs a lot of money.
When you buy a camera kit...like one that comes with your typical 18-55mm lens...those lenses are typically f/3.5 - 5.6. Which means that when you zoom out to 18mm, the biggest aperture you can use is 3.5. And when you zoom out to 55mm, the biggest aperture you can use is 5.6.
Make sense?