The Captivate help files give the following definition for an LMS:
"You can use a learning management system (LMS) to distribute a computer-based tutorial created using Adobe Captivate over the Internet. A learning management system is used to provide, track, and manage web-based training."
An LMS offers many services to both teachers and students involved in eLearning activities. The following list states some of them:
An LMS is a website that is able to host your eLearning courses.
An LMS maintains a list of teachers and students. Thanks to this listing, an LMS can be used to enroll students in online courses and to define one or more teacher(s) for each course.
An LMS is able to enforce the pedagogical decisions of the teacher. For example, the LMS can be programmed to give access to the next part of the course only if the current activity has been completed. Some LMS can also enforce branching by automatically providing an additional activity for those students...