Social networking allows individuals to connect online through communities and share information. Popular social networking sites include Facebook, which has over 200 million active users, and Twitter, on which 3 million tweets are sent daily. These sites allow users to stay connected with friends and family, share photos and updates, and develop new relationships, all for free. While over 400 social networking sites exist, Facebook and Twitter are among the most widely used, with women over 50 being the fastest growing users of Facebook.