Genealogy (from Greek: γενεά, genea, "escent"; and λόγος, logos, "knowledge") is the study and tracing of family lineages and history. Genealogical research is a complex process that uses historical records to establish biological, genetic, or familial kinship. Reliable conclusions are based on the quality of sources, ideally original records, the information within those sources, ideally primary or firsthand information, and the evidence that can be drawn, directly or indirectly, from that information. In many instances, genealogists must skillfully assemble indirect or circumstantial evidence to build a case for identity and kinship. All evidence and conclusions, together with the documentation that supports them, is then assembled to create a cohesive "genealogy" or "family history." Traditionalists may differentiate between these last two terms, using the former to describe skeletal accounts of kinship (aka family trees) and the latter as a "fleshing out" of lives and personal histories. However, historical, social, and family context is in any case essential to achieving correct identification of individuals and relationships.