Difference b/w capital and deffered revenue expenditures.

Pls clarify the difference b/w deffered and capital exp.  If we enjoy the benefits of the exp. for more than one yr. called as D.R.E. Well then what does capital exp. means? If we buy one machine for the factory it is a capital exp. We enjoy the benefit of that asset upto sum yrs. i.e., upto the life time of that machines. Then my doubt is why it is becoming a Capital exp. and why insurance premium is becoming a D.R.E.