Reference works provide a good starting point for research. They are sources designed not to be read from cover to cover but to be used to get key facts about a topic. They provide quick introduction to your subject by covering a lot of points briefly; in-depth background on some of the major people and/or key elements of your topic; vocabulary to use for searches in other resources and ideas for additional resources.
Journals are scholarly publications, published on a regular basis, that keep the academic community abreast of current research in various fields. Each issue of a journal has several articles, depicting research that has been conducted and researchers want to share with colleagues in their discipline.