A Learning Management System or LMS is a server system that provides support for training activities. In Bentley's case, its LMS is called the Learn Server and it includes everything from signing up for live training courses to taking on-demand courses.
The key to this system is the word "management". As a Learner finishes a course, the LMS tracks this activity for further processing, including recording the completion to the learner's online transcript. The LMS also directly manages all on-demand course progress right down to how much of a video the learner watched or what page or slide the learner has completed.
As a result of this level of management granularity, the learner is able to pause and resume on-demand courses at any time, returning to exactly the same place they left off. More importantly, they can resume the course on any computer as long as they have access to the internet.