Learning Management Systems (LMS) and Virtual Learning Environment (VLE) are used to mean more or less the same thing. For example, the term LMS is used for Blackboard Learn in Australia and VLE for the same system in the UK. As I’m in Australia today, I’ve used the term LMS in this blog.
For me, LMSs are like keystone species of biological ecosystems. Keystone species play a crucial role in maintaining the balance of an ecosystem, which would collapse if that species was removed.