World history, global history or transnational history (not to be confused with diplomatic or international history) is a field of historical study that emerged as a distinct academic field in the 1980s. It examines history from a global perspective. It is not to be confused with comparative history, which, like world history, deals with the history of multiple cultures and nations, but does not do so on a global scale. World History looks for common patterns that emerge across all cultures. World historians use a thematic approach, with two major focal points: integration (how processes of world history have drawn people of the world together) and difference (how patterns of world history reveal the diversity of the human experience). History (from Greek ἱστορία - historia, meaning "inquiry, knowledge acquired by investigation" It is the study of the past, specifically how it relates to humans. It is an umbrella term that relates to past events as well as the discovery, collection, organization, and presentation of information about these events. The term includes cosmic, geologic, and organic history, but is often generically implied to mean human history. Scholars who write about history are called historians. Events occurring prior to written record are considered prehistory. History can also refer to the academic discipline which uses a narrative to examine and analyse a sequence of past events, and objectively determine the patterns of cause and effect that determine them. Historians sometimes debate the nature of history and its usefulness by discussing the study of the discipline as an end in itself and as a way of providing "perspective" on the problems of the present.