“Is that your father? You don’t look anything like him at all!”
“Oh, I take after my mother. Everyone on my mother’s side of the family has this hair color.”

If you draw a line through the middle of your family tree, one half will be your father’s side—your father, his siblings, his parents, his grandparents, etc.—and the other half will be your mother’s side—your mother and all of her family. You and your siblings probably have traits from both sides.