Interconnectedness is one of many concepts gaining popularity as part of the terminology of a worldview which sees a oneness in all things. A similar term, interdependence, is sometimes used instead, although there are slightly different connotations. Both terms tend to refer to the idea that all things are of a single underlying substance and reality, and that there is no true separation deeper than appearances. Some feel that 'interconnectedness' and similar terms are part of a contemporary lexicon of mysticism, which is based on the same core idea of universal oneness.