Moodle is a free and open-source learning management system that provides educators with tools to create online courses with forums, assignments, quizzes, journals and more. It allows for easy creation, management and sharing of course content. Moodle has a modular design that makes adding new activities simple. It also offers features to track learner participation, provide grades and feedback, and integrate with external systems. With its social constructionist principles, Moodle aims to promote collaborative learning through learner-centered activities.