The opposite of synchronous. Not occurring at the same time. In digital learning asynchronous often refers to discussion boards or applications that allow learners to participate in a conversation or discussion at different times. While learners will use a common platform (say a discussion forum) they do not have to gather in that forum at the same time in order to participate in the discussion. They can read and post comments on their own schedule independent of other learners.
Synchronous
To exist or occur at the same time. In digital learning this often means a live session where all participants meet and interact with each other at the same time in the same virtual space. The virtual space is often a platform such as Zoom or Collaborate that supports real time audio, video and text chat interactions.