History is the study and analysis of accounts of past events, or the interpretation of physical materials in relation to written accounts. Only a small range of historical "facts" can actually be verified. Most researchers who study historic accounts, historians, are aware that our present perspective colors our interpretation of past events. Therefore, a number of opinions and interpretations of historic events can be presented, and may be of equal value. However, opinions and analysis based on primary sources—documents produced during or shortly after the period in question—are usually considered the most valuable.
See also: Wikisource:Historical documents.