For example when greeting. Englishman asks me: How are you? I answer: I`m fine. Thanks If a russian asks me "Как дела?" I will answer: "Хорошо. Спасибо" In this case "Хорошо" is equal to "I`m fine". Also "хорошо" is russian equivalent of "good", "well", "OK" and is used in the same cases, in which all the words are used in English. Unfortunately I don`t know Korean :-(

Actually, "Хорошо" is a short form of adjective "Хороший"(=good). If you use "Хорошо" as a PREDICATE, it would be equal to "it is nice, it is pleasant" (e.g.: здесь хорошо гулять = it is nice to walk here). if you use "Хорошо" as an ADVERB, it would be equal to "well, good, nice" (e.g.: хорошо сказано = well said). And, finally, if you EXPRESS that you AGREE with something, "Хорошо" will be equal to "very well!, all right!, agreed!, OK!, okay!, good!". I hope my answer would help you :)