Social constructionism is a term that defines a particular view of education. It acknowledges constructivism as a description of what each learner experiences, while focussing on the power of constructing artifacts (like text) within a social environment.
From this point of view, education is best served by creating experiences that would be best for learning from the learner's point of view, rather than just publishing and assessing the information you think they need to know. Each participant in a course can be a teacher as well as a learner. A 'teacher' in this environment is an influencer and role model of class culture, connecting with others in a personal way that addresses their own learning needs, and moderating discussions and activities in a way that collectively leads students towards the learning goals of the class.
Moodle tries to promote this view, but is not constrained by it.