This is the 848th most frequent Korean word.
확인
"확인" means "confirmation" or "verification" in English.
The word "확인" is used here as a noun to mean 'to check or verify,' often used with the verb "하다" or "해 주세요" to make a polite request.
문서를 확인해 주세요.
Please check the document.
Here, "확인" refers to 'verification,' and it illustrates completion of the act of confirming or checking as combined with "완료하다" meaning 'to complete.'
확인을 완료하였습니다.
The verification has been completed.
In this sentence, "확인" is used as a noun for 'confirmation,' referring to the process of verifying something like a password.