I don’t think that’s quite right. K-1 is the fiancé(e) visa: it’s to allow someone to whom you are not yet married to enter the U.S. in order to marry.
If a U.S. citizen marries abroad, they would file an I-130 petition for their spouse to immigrate in the IR/CR category; they would then be able to file for a K-3 non-immigrant spouse visa so their spouse could accompany them to the U.S. while the I-130 petition was processed.
If a U.S. citizen marries abroad, they would file an I-130 petition for their spouse to immigrate in the IR/CR category; they would then be able to file for a K-3 non-immigrant spouse visa so their spouse could accompany them to the U.S. while the I-130 petition was processed.