My Question, What Is Steemit ?

I am a new person in the world of local and international steemian. Is there someone who wants to help me in understanding this steemit?

I think I am getting interested in steemit, when I hear stories from my friends who are successful in writing and publications that they upload, I feel compelled to be a steemian, the only thing that is very unfortunate is I have not been able to study this steemit well. But I am very confident, that I may someday be like those who have been successful.