Facebook News Feed vs Live Feed

Facebook implemented this seperation of what was the news feed in to something called a live feed and a news feed. I have been trying to figure out what is the difference. How does some people's stuff end up in my news feed as opposed to others. I honestly can't figure out the logic of it. So if anyone has any answers, information, links...SOMETHING...send them my way. Because I'm sure if I'm confused my students also have to be confused and will be asking me for an answer as soon as they realize they are confused....lol.