A family tree, or pedigree chart, is a chart representing family relationships in a conventional tree structure

Tree structure

A tree structure is a way of representing the hierarchical nature of a structure in a graphical form. It is named a "tree structure" because the classic representation resembles a tree, even though the chart is generally upside down compared to an actual tree, with the "root" at the top and the...

. The more detailed family trees used in medicine

Medicine

Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

, genealogy

Genealogy

Genealogy is the study of families and the tracing of their lineages and history. Genealogists use oral traditions, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kinship and pedigrees of its members...

, and social work

Social work

Social Work is a professional and academic discipline that seeks to improve the quality of life and wellbeing of an individual, group, or community by intervening through research, policy, community organizing, direct practice, and teaching on behalf of those afflicted with poverty or any real or...

 are known as genograms.
Genealogical data can be represented in several formats, for example as a pedigree

Pedigree chart

A pedigree chart is a diagram that shows the occurrence and appearance or phenotypes of a particular gene or organism and its ancestors from one generation to the next, most commonly humans, show dogs, and race horses....

 or ancestor chart. Family trees are often presented with the oldest generations at the top and the newer generations at the bottom.