Online courses can help you learn Hadoop by introducing you to the basics of it, having you work through exercises and create programs that use it, and seeing how it connects to other parts of the data warehouse. Some courses require no programming experience. Others assume that you understand programming but need specific experience with Hadoop. Some courses are practical, offering hands-on experience and leading to the creations of programs that can be used right away. Others are theoretical and explain the nature of Hadoop and the underlying principles of big data. The courses build on each other, with some leading to Specializations and online degrees.