Facebook is a social media platform founded by Mark Zuckerberg, Eduardo Saverin, Andrew McCollum, Dustin Moskovitz, and Chris Hughes in February 2004. Originally called "Thefacebook," it was initially developed as a platform exclusively for Harvard University students. However, its popularity quickly spread to other Ivy League universities and eventually expanded to colleges and universities across the United States and Canada.

In 2005, Facebook's domain name was changed to simply "Facebook" and opened its doors to high school students. Later that year, it further expanded its reach to include anyone above the age of 13 with a valid email address. Facebook's user base grew rapidly, attracting millions of users from around the world.

The year 2006 marked a significant milestone for Facebook when it introduced the News Feed feature. This feature allowed users to see updates from their friends and pages they followed on a single, constantly updating page. Initially, the News Feed faced some backlash from users who felt their privacy was being compromised. However, Facebook addressed these concerns by implementing privacy controls that allowed users to customize their settings.

In 2007, Facebook launched the Facebook Platform, which allowed third-party developers to create applications (apps) that could be used within the platform. This move opened up a new ecosystem of games, productivity tools, and other apps that expanded Facebook's functionality and engagement.

Facebook experienced exponential growth and global expansion in the following years. It surpassed MySpace as the most popular social networking site in 2008 and continued to add features such as the "Like" button, photo tagging, and the ability to create business pages and groups. In 2010, the company reached another major milestone by surpassing 500 million active users worldwide.

In 2012, Facebook acquired the photo-sharing platform Instagram, which had gained significant popularity among mobile users. This acquisition further solidified Facebook's dominance in the social media landscape and expanded its user base to include Instagram's millions of active users.

Another major acquisition took place in 2014 when Facebook purchased the messaging service WhatsApp, which had a large user base in emerging markets. This move further solidified Facebook's presence in the mobile messaging space.

Facebook's initial public offering (IPO) took place in May 2012, making it one of the largest technology IPOs in history. The company's stock faced some volatility initially but eventually stabilized and continued to grow.

However, Facebook faced several controversies and challenges over the years. In 2018, it was revealed that the political consulting firm Cambridge Analytica had harvested the personal data of millions of Facebook users without their consent. This incident sparked a global conversation about user privacy and data protection, leading to increased scrutiny of Facebook's practices and policies.

In response to these challenges, Facebook made efforts to enhance user privacy controls and implement stricter guidelines for third-party app developers. The company also faced criticism for its role in the spread of misinformation and the manipulation of public opinion during elections and other political events.

Despite these challenges, Facebook remained one of the most widely used social media platforms globally. It continued to innovate and introduce new features such as Facebook Live, Marketplace, and Watch, which focused on video content.

As of my knowledge cutoff in September 2021, Facebook remains a dominant force in social media, with billions of active users worldwide. However, it is essential to note that developments may have occurred beyond this point that I am unaware of.