Open Access is making research publications (e.g. Books, journals, articles, reviews, etc.) freely available to all. Open Education is learning materials that others can use, change and enhance because the creators of the materials have given others permission to do so. Open education resources (OER) can include presentation slides, lesson plans, lecture videos, textbooks, worksheets, podcasts, etc.
Primary Sources include resources that give first-hand evidence, experiences and raw information. A primary source can be a literary work, art work, maps, statistical data, transcripts, etc.
Secondary Sources provides second hand-knowledge and commentary from other researchers. A secondary source can be a scholarly article, reviews, academic books, etc.