What does it mean to be authentic?

To be authentic means to not only become the character but to live and breath as the character. Denzel Washington, Will Smith, and Angelina Jolie are examples of that.When they get a new role in a movie they try and do things that will help them understand the character much more, they go out and do things that can help bring them closer to the character. For example when Denzel was working on Training Day he started to walk, talk and look like the role he was assigned to play. In one of his interviewed he said he gained 40 pounds to help him understand and become much more closer to the character he was trying to be and that's what being an authentic is all about, you need to live as the whoever you are trying to play or else it isn't going to be real and it won't look believable.