Othello?

So ever since I can remember, there has been this board game in my basement called Othello. Just a green board with black/white pieces. So if the people of this sub don’t mind me asking, what IS othello. All I’ve really done with it is put the pieces on the board and flip them over in the little grooves. But no idea how to play it or why we have it. And everyone in my family either doesn’t know we had it, or acts like it’s cursed and dares not approach.