This document discusses social networking services and focuses on Facebook. It provides details on what a social networking service is, how Facebook was founded in 2004 by Mark Zuckerberg and others, and how it initially launched at Harvard before expanding to other universities. Key statistics are given on Facebook's user base, revenue, expenses, and criticisms around privacy and other issues. Both the positive impacts of staying connected with friends and the potential negative impacts like cyberbullying are acknowledged.