Both blended learning or the flipped classroom are pedagogical models that use technology to enhance active learning and student engagement inside and outside the classroom. By using a hybrid course design, both models balance and combine face-to-face and online activities in a way that will challenge students’ and the instructor’s roles in the learning process.
The most notorious difference between them will be face time. Adopting a Blended Learning model implies that face-to-face time will be reduced and some of the (weekly) meetings will be replaced with online content and/or activities. A flipped classroom model, on the other side, implies that meetings will not be reduced but class time will be repurposed to include students’ activities in the class, and listening to lectures or explanations at home via video or other techniques.
This document from EDUCAUSE explains in a brief and clear way what is the Flipped Classroom.