Genealogy is the study of a family's lineage. Many people want to trace out their family trees, or simply find a specific person in a family's past and connect him or her to other members of that family. This discipline is interested solely in who is in a family and who each person is related to, as opposed to the more general study of family history, which might also track dates of birth and death, occupations held by family members, and other important facts about their lives and deaths. While some people, on occasion, refer to this larger field as genealogy, the term is better viewed as a subset of a greater discipline.
Historically, genealogy was a very important field, because family connections between nobility were crucial to the idea of inheritance and the passing down of titles and rulership. In many societies, for example, if a king had no direct heir, the next closest heir would have to be found. Detailed genealogical records ensured that the passing down of titles would never have to rely on incomplete facts. Despite this, many differing records would often crop up, allowing multiple people to lay claim to a title of rulership or inheritance.
Genealogy may also play an important role in helping to restore families that have been torn apart by some larger circumstance. In the many decades after World War II, for example, genealogists have helped people displaced by the war rediscover their relatives who remained in Europe. Famines and social situations may also cause such diaspora, and the discipline may help people rediscover this lost history; many Irish families, for example, use genealogical records to help rediscover family that has been separated for two or three generations, since their families emigrated from Ireland. As another example, after the popularization of Alex Haley’s book Roots, there was renewed interest among the African American population in tracing their own family roots.
With the Internet, it is now much easier to research family connections than at any other time in history. Despite the rather large amount of false information and scams that pervade the online genealogical world, there are many legitimate and incredibly valuable resources available, allowing people who, 50 years ago, would have had to spend many years tracking down their family roots to do so in months or even weeks. The affordability of genetic analysis has also opened new doors in the field, letting normal people access scientific evidence of a connection to another person or family branch. While genetic analysis isn't entirely accurate, it is so close that it is considered by most people to be certain evidence of a family connection.