Who is Charlie from Eclipse and what is their importance?

Charlie is Bella's father. Charlie is the sheriff in Forks. Charlie remains happily clueless as to the true nature of the Cullen family. However, Charlie dislikes Edward and does not approve of his relationship with Bella. For this reason, Charlie often serves as an obstacle between Edward and Bella. Despite this, Bella has doubts about the impact of her future on Charlie, specifically how it will impact Charlie when she becomes a vampire like Edward.