You add private profiles for yourself and living parents, grandparents, etc.
At FamilySearch, tree-building has a very different structure. The site has just one shared, global Family Tree, with (ideally) a single profile for each deceased person, for a total of about 1.5 billion names. You add private profiles for yourself and living parents, grandparents, etc. Working backward through the generations, you add new profiles for deceased relatives who aren’t in the Family Tree and connect to the profiles of ancestors who are in the Family Tree. Once you’ve connected to existing profiles, that person’s tree data automatically appears.