The evolution of the Internet began in 1969 with the creation of ARPANET by the US Defense Department to connect universities. Major developments included the first email in 1971, establishment of Internet protocols in 1982, launch of the World Wide Web in 1991, the first web browser and online shopping in 1993, and the founding of companies like Amazon, Google, Facebook, and YouTube which demonstrated the Internet's commercial potential. By the late 1990s and 2000s, search engine optimization, pay-per-click advertising, social media, and blogging had become widespread as the Internet continued to grow exponentially in users and functionality.