Metaphysics is the study of Being, existence and reality, both in terms of their meaning and in terms of speculative questions regarding the base existential and cognitive requirements of these concepts. Consequently, metaphysics can also be seen at a higher level of specificity as a conceptual study of beginnings and endings, the role of modalities (e.g., necessity, possibility, actuality), and investigation into what the most general or inextricable/indispensable classes or sets of entities are.