Coursera is truly a name known by all. It is a world-wide online learning platform founded in 2012 by Stanford University's computer science professors Andrew Ng and Daphne Koller that offers massive open online courses (MOOC), specializations, degrees, professional and master track courses.
Coursera works with universities and other organizations to offer online courses, certifications, and degrees in a variety of subjects, such as engineering, data science, machine learning, mathematics, business, financing, computer science, digital marketing, humanities, medicine, biology, social sciences, and others. (Source:Wiki)