For anyone as confused as me (OP’s link let to a blank page for me, so no help there), I generated a brief summary of the Real ID Wikipedia article.

Regulations now in place still are less stringent as I know them to be for domestic flights, and ID regulations in general, in European countries, but I now know that in the US there has always been a broad resistance against mandatory ID’s, mainly because of the implications on personal freedom and privacy.
This probably also explains the somewhat heated comments in this thread.

Here is the summary:

The Real ID Act of 2005 is a federal law that establishes minimum security standards for state-issued driver’s licenses and identification cards in the United States. Passed in response to the 9/11 attacks, its primary purpose is to enhance national security by ensuring that identity documents used to access federal facilities, nuclear power plants, and board commercial airline flights are more secure and standardized.

The law:

• Requires states to verify applicants’ identity, Social Security number, legal status, and address using official documentation.
• Mandates enhanced security features on IDs and digital storage of application documents.
• Establishes electronic sharing of ID and driver history databases between states.
• Requires IDs to display a standardized format, including a photograph, full name, date of birth, signature, and (as of recent updates) gender marker.

States must issue two versions of IDs:

1.) A Real ID-compliant version (marked with a star), valid for federal purposes.
2.) A non-compliant version (with a disclaimer like “Not for Federal Use”) — still usable for driving or local identification.

Enforcement was repeatedly delayed. The final phase began on May 7, 2025, with full enforcement slated for May 5, 2027.

All 50 states and U.S. territories are now certified as compliant. Starting in 2025, TSA began enforcing Real ID requirements at airport checkpoints.