Facebook is a social networking website that allows users to create profiles to connect with friends and family and share photos, videos, and personal information. It was founded in 2004 by Mark Zuckerberg and initially launched at Harvard before expanding to other universities and the public. The mission of Facebook is to make the world more open and connected by giving people the power to share. While Facebook allows users to connect with others, it is important for users to adjust privacy settings and be cautious about sharing private information publicly.