What is asynchronous vs. synchronous learning?

Asynchronous learning means that students can engage with course material on their own time (while adhering to deadlines). In contrast, synchronous learning means that all students participate in a learning experience at the same time. For example, a recorded lecture that students can watch at any time in the days leading up to a group activity is asynchronous course content, and a live lecture that can only be watched in real-time is synchronous course content.