Massive open online courses (MOOCs) are online courses aimed at unlimited participation via the web. MOOCs offer courses free of charge and allow students to enroll anytime. While the first MOOCs date back to 2006-2007, the term was coined in 2008. In 2011, MOOCs grew substantially in popularity. There are two main types of MOOCs: connectivist MOOCs (cMOOCs) which emphasize peer-to-peer learning and connections, and xMOOCs which focus on structured content and assessment. MOOCs can also be categorized by their synchronous or asynchronous nature, content delivery approach, and learning goals.