A MOOC is a Massive Open Online Course. These are online college classes that often have enrollments of many tens of thousands of students in a single class. The concept was pioneered by Harvard and MIT in a joint project called edX, and with the University of Texas joining edX, the movement is going to expand dramatically.
With the cost of a college education now costing many tens of thousands of dollars a year, most college students can't get a four year degree without nearly bankrupting their parents and/or taking on staggering student loans. And employers are not always satisfied with the quality of college graduates as many four year institutions have been spending more on amenities to justify the high tuition while shortchanging actual instruction.
MOOCs have the potential to make getting a good job much less expensive, and the traditional four year colleges had better beware....the dis-intermediation is being caused by high speed broadband. Like the sudden disappearance of music stores, which took only ten years, expect many four year schools to be gone a decade from now, as parents and young people figure out that there are cheaper and better ways to get prepared for the work world.