This is the 7463rd most frequent Polish word.
koreä
The word "koreä" does not exist in Polish. It might be a typo or misspelling.
In this sentence, 'Koreä' is used as a proper noun referring to the country of Korea in a geographical context.
Koreä jest krajem w Azji Wschodniej.
Korea is a country in East Asia.
Here, 'Koreä' is again a proper noun, demonstrating national characteristics or achievements.
Koreä rozwija swoją gospodarkę bardzo szybko.
Korea is developing its economy very quickly.
In this example, 'Koreä' represents the destination of travel using the preposition 'do' indicating motion towards a place.