These are two enormously different stories, not least because the Bradbury is a short story (in his Martian Chronicles collection), while Charlotte's Web is a short novel. Also, Rains could be viewed as something of a horror story, since it is basically an end of the world post nuclear holocaust story, and the one living thing in it, a dog, dies either from radiation poisoning or thirst or starvation, I've never been certain which, nor does it really matter. Charlotte's Web does have the mother spider die, but it is presented as a natural thing.
Let's say that one story is a total downer while the other is an uplifting story of hope, growth, love.
