Identity is a complex issue, but this site focuses upon the aspect of identity based upon family lineage. With this comes many things such as culture, values, nationality, physical appearance, etc. The primary thing to understand is that genealogy deals with biological origin and grounds this in research of documented facts.
This is distinct from various aspects of identity that can be adopted by oneself with respect to social performative behavior. Such things might include gender performance identity, sports team identity, adopted religion or political party affiliation.