South Korea – Korean Alphabet

What’s the main difference between Chinese and Korean language?
(Sorry for this naive text; it’s just from a person who has not so much idea about languages! 🙂 )
In Chinese, there is no alphabet; they have many (many, many!!!) characters, but no single letters. So I thought, it’s the same with Korean language. But it’s not! Korean alphabet exists and the number of letters in Korean is not so much different from e.g., English alphabet.