login system with CI 3.0

Hi

I am a junior php programmer. I started to use CI (CI 2) last week. I love it. This system is simple but great. Well.. I am doing a login system with CI 2 but I see now, that the fresh version is 3.0. I would like to ask that what's news in CI3's user Management ( I use session and mysql database)
I thank you the answers! Have a nice day!