A description of the Living Reviews concept, from their website:
Articles are solicited from leading authorities and are intended for physicists at or above the graduate-student level. The Articles in Living Reviews provide up-to-date critical reviews of the state of research in the fields they cover. Articles also offer annotated insights (and where possible, active links) into the key literature and describe online resources available in these fields. Living Reviews is unique in maintaining a suite of high-quality reviews; its articles are subjected to strict peer-review and are kept up-to-date by the authors. This is the meaning of the word "Living" in the journal's title.