Here's a description from onlinecollege.org:
In a flipped classroom, students watch lectures and supplemental materials for their classes at home, usually pre-recorded by their instructors and uploaded to the web. Classroom time is then used for answering student questions, helping with homework, and other activities that help students apply what they've learned.Once again, the idea here is to use the technology for what it does well to free the teacher to do what the teacher does well. In some examples the technology provides the individualized instruction. In this example the teacher provides the individualized instruction.
The key to good educational uses of technology remains the same: the teacher delegates to the technology the tasks that do not require the teacher's personal and professional attention. The teacher retains those personal and professional tasks that require creativity, improvisation, and customization - the parts that are founded on knowing each student and what that student needs to be motivated and to progress.
What is the highest and best use of the teacher's time and class time and how can we leverage technology to allow the teacher to do more of that in class?