One of the world’s best-known online learning resources, Coursera has several thousand courses from leading educational providers. Those include elite universities such as Stanford and Princeton, as well as big-name businesses such as IBM and Google. Coursera offers several thousand free courses across a plethora of different subject areas. Whether you’re looking for an introduction to programming or you want to get to grips with machine learning, there’s a course on Coursera for you. Another benefit of using the site is that you can complete collections of related courses (known as “specializations”) to really sharpen your knowledge across a particular topic.