Coursera is an American online learning platform founded by Stanford professors
Andrew Ng and Daphne Koller that offers massive open online courses (MOOC), specializations, and degrees.
Udemy.com is an online learning platform. It is aimed at professional adults.
Unlike academic massive open online course (MOOC) programs which are driven by traditional collegiate coursework,
Udemy uses content from online content creators to sell for profit.
Udemy provides tools which enable users to create a course, promote it and earn money from student tuition charges.
Udacity, Inc. is a for-profit educational organization founded by Sebastian Thrun, David Stavens, and Mike Sokolsky offering massive open online courses.
Udacity is the outgrowth of free computer science classes offered in 2011 through Stanford University.