Difference between a nucleophile and base?

I think your source of info isn't reliable.. A base is a proton (hydrogen) acceptor.. That means that it accepts protons form acids. I say protons, because a hydrogen ion consists of a proton, so calling a base a proton or hydrogen acceptor is more or less the same thing. It accepts hydrogen from the H30 which is commonly written as H+. A nucleophile is a proton lover. That means it attacks centres of positive charge. e.g. a bond between a carbon and an oxygen. The oxygen is more electronegative (attracts electrons more strongly) than carbon. So this makes oxygen slightly more negative and carbon slightly more positive. So a nucleophile will come and attack the carbon, which will break the bond between the carbon and oxygen, and then form a new bond between the carbon and the nucleophile. Hope this helps!