History is the systematic study of the historical past. Events prior to the invention of written language are often regarded as prehistoric history. “alogy” is a broad umbrella term containing both chronological and sociological studies of the past. Historians specialize in particular fields of history such as archeology, genealogies, military history, and social history. Often they conduct research as part of their daily work, or for a special purpose such as writing textbooks or non-fiction books on specific topics.
One type of historian is the teacher who teaches the history of a particular region, time or country. In the United States, history teachers generally teach American history, which includes U.S. history courses. Another type of historian is the writer who analyzes past events for political, societal or scientific purposes. Some writers specialize in documentation, while others write fictional works.
Historical researchers examine historical documents and sources in order to support their arguments. They then interpret the information that they discover in order to offer an interpretation or explanation for their findings. Other historians do public history, working for local, state or national organizations to collect data on important issues that shape public policy. There are also historians who conduct research as a private professional, often for a living. In all types of history, there are specialists who can provide advice as to how to conduct historical research and what types of sources to use, what types of information to record, how to interpret the data, what publications are useful and what publications should be avoided.