The relation between Chinese and Japanese characters.

I took Japanese 101 at Rutgers University, so I have a little familiarity with it. My question is that if Japanese kanji are the same as Chinese characters. They would only be the same in meaning. I think they came into use in Japan during the so-called "Nara period", which is when Buddhism also came into Japan. Not sure though. Anyway, arigato guzaimasu.