ge·ne·al·o·gy [jnee ólljee ] (plural ge·ne·al·o·gies) noun

1.  study of the history of families:  the study of the history of families and the line of descent from their ancestors
2.  family history:  a pedigree or line of descent that can be traced directly from an ancestor or earlier form, especially that of an individual or family
3.  family tree:  a chart or table that shows the line of descent from an ancestor or earlier form, especially that of an individual or family

[14th century. Via French généalogie from, ultimately, Greek genealogia , from genea "race, generation."]

Jerry & Dottie Nelson's Family Group Sheet
(Main starting point - follow the name links from there)