Korean doesn't use kanji. It uses hanja.
While Korean uses a syllabary just like English, the sino-Korean words still have the underlying hanja. If you look up those words in the dictionary, it will show the hanja. [0]
From my understanding there are several usages of hanja to this day:
- Korean names. For the most part, given names will have hanja chosen by the parents/grandparents/family. However recently it's becoming more common to have pure hangeul names, or english/foreign names, with no associated hanja.
- To disambiguate homographs/homonyms. This is common on Korean tv shows.
- To represent countries, politicians, and surnames on news articles. For example, 朴 (surname Pak/Park) and 美 (USA). Here is a random article example. [1] and a list of common hanja that pops up. [2] Side note, it's humorous to me that the hanja used for USA is also the hanja for 'beauty' (미).
- For days of the week and months, I saw hanja being used somewhat commonly.
- To guess the meaning of unknown words. If you know a certain hanja reading like 비 or 경 then it makes figuring out words a bit easier.
[0]: https://en.dict.naver.com/#/entry/koen/27ed7d6b4161442885572...
[1]: https://www.chosun.com/politics/politics_general/2021/03/25/...
[2]: https://old.reddit.com/r/Korean/comments/km01fv/short_list_o...
edit: clarified about modern Korean naming practices.