Current USA to Korea visa rule?

I've read (for example South Korea travel visa - When do I leave?) that U.S.A. citizens can just go to Korea for 90 days as easily as to Schengen, i.e., no visa. Has there been a change?
The reason I wonder is (1) the school I was considering has a list of countries that don't need a visa, and (2) a website that appears to be "official" has a link to a similar list that also does not include USA, but then follows the link with another list that does include USA.
From the comment and first answer, it sounds like if I am just a tourist, I need no visa, but if I intend to also attend a class, I do need one? To complicate it further, I just found out about a "class" that sounds too good to be true.
Pictures about "Current USA to Korea visa rule?"



Can you travel to Korea right now from USA?
Entry and Exit Requirements & Movement Restrictions. Are U.S. citizens permitted to enter? Yes. * Pre-departure testing required for all inbound travelers to Korea, including those who have been vaccinated.Is South Korea issuing visas now?
Visa Not Required for South Korea According to the South Korean visa policy, visa-free travel is now only possible with a K-ETA (see above). The K-ETA can be obtained in minutes through a simple online application and is valid for 2 years from approval. It allows multiple entries to South Korea during its validity.South Korea Travel 2022 |Foreigners traveling to South Korea|Korea Visa Free Entry.
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Charles Parker, RODNAE Productions, RODNAE Productions, RODNAE Productions