Per Udemy's website,  "Udemy is ... the world’s online learning marketplace, where 9 million+ students are taking courses in everything from programming to yoga to photography–and much, much more. Each of our 35,000+ courses is taught by an expert instructor, and every course is available on-demand, so students can learn at their own pace, on their own time, and on any device . . . " For more information about the online course site, read the Udemy | About Us.