The design and development of Moodle is guided by a particular philosophy of learning, a way of thinking that you may see referred to in shorthand as a "social constructionist pedagogy". (Some of you scientists may already be thinking "soft education mumbo jumbo" and reaching for your mouse, but please read on - this is useful for every subject area!)
This page tries to explain in simple terms what that phrase means by unpacking four main concepts behind it. Note that each of these is summarising one view of an immense amount of diverse research so these definitions may seem thin if you have read about these before.
If these concepts are completely new to you then it is likely that these ideas will be hard to understand at first - all I can recommend is that you read it carefully, while thinking about your own experiences of trying to learn something.