Is a 35mm better than the 18-55mm? Besides being a fixed mm lens, what's different/better about it? What type of shooting is it best for? Is it a wider field of view?
We are venturing into vagueness now.

But the 35mm f/1.8 is $200, and the 18-55mm zoom is $100. That is one clue. The zoom is only f/3.5 to f/5.6. The fixed lens only does 35mm, but we can assume this one does a better sharper job than this zoom. Both have the same field of view if zoom is at 35mm, but the zoom is more versatile, 18-55mm. The fixed lens will not do 18 or 55 mm.
If you want sharper, there are several better zooms, like say 24-70mm for $1900. It will give the little fixed lens a very good run on sharpness, and no doubt beats any $200 lens. It is f/2.8, which is between f/1.8 and f/3.5. And of course there are lesser price zooms, like 16-85mm, which are still incredibly awesome lenses.
So, there are features - wide aperture, and sharpness, and of course price and versatility considerations.
Never only one answer. We do tend to like the versatility of zooms, but good ones cost more money.