Blended learning combines online and traditional classroom learning. It involves some learning occurring online, where students can control their pace and path, while some learning takes place in a traditional classroom setting led by an instructor. There are different models of blended learning, including rotation models where students rotate between online and classroom activities, and flex models where most content is delivered online but in a traditional school setting guided by teachers. Blended learning provides benefits like flexibility, effectiveness, efficiency and personalization, but also potential disadvantages like distraction and weakened concentration if not implemented properly.