got a point and shoot camera.. kodak..14 megapixels. dpi it shoots at..480. When I enlarge it at 100% in photoshop..it looks grainy, pixel grainy on the screen. 

I've noticed that with every digital camera. 

I used to use 35mm slides.. when you scan it at 300 dpi..it shows up without any grain. 

Why? is there a setting I don't seem to be getting? 

thanks a gazillion in advance for answers. I've been traquilized by turning coloured into b & w in photoshop.. so I won't turn bearish..