I had a great conversation over the weekend trying to explain 'what is a genealogist?' A genealogist is a person that knows what records exist and knows where to find them. They know how to create proof arguments to "prove" a fact that lacks documentation. They help you determine your great-great-grandmother's maiden name. But they also create a timeline of your family's hardware business from the 1800s and track down the building it was in. They give you a history of your historic home. They go to the cemetery and take a picture of your ancestor's headstone. They help you identify people in old photos.
And they solve mysteries. There are genealogist that specialize in forensic genealogy and try to solve missing persons cases, unidentified body (John / Jane Doe) cases, adoptions, DNA analysis and search for missing heirs.
And sometimes they wear many hats. There are genealogists who are speakers at conferences, educators, librarians at archives, and authors of genealogical research.