Sorry for the dumb question from a dumb French.
In France, primary sources for birth, marriage and death records are public registries, mandatory since Ordonnance de Villers-Cotterêts in 1539. Until 1792, those registries were under the responsability of the (catholic) Church, and since the Revolution, maintained by the état-civil office of each commune.
Most of those registries have been preserved from the turmoils of history, and are now available on-line and for free for most of France départements, courtesy of public archives, at least for people born before 1920.
As I understand from the few American profiles I've started to look at in some details, there is no such facility in the US, and on American profiles most sources are quoted through a private genealogy service such as Ancestry or FamilySearch.
Is it really the only way to search and link to records in the USA? For example if I want to find out more about the linked profile, e.g., birth place and parents, where should I start?
Disclaimer : I've tried to find out in the Help pages, but they lack a "Sources 101 - for dummy foreigners" section