Moodle is a free and open-source learning management system (LMS) that can be used to create online courses with various features for course management, learner management, and content delivery. Some key features of Moodle include modules for assignments, quizzes, forums, choices, surveys, and more. It also includes tools for grading, tracking learner activity, managing files, and integrating calendars and events. Moodle provides advantages like low cost, flexibility, and active learning opportunities through discussion forums and group work. However, it may lack some advanced assessment and content management capabilities available in proprietary LMS solutions.