Hanja (한자) come from Chinese characters, but Hanja are used in Korean even today - everywhere from official documents to newspapers and signs and even names. Knowing Hanja and their meanings can help you to improve your Korean at any level, and at higher levels it's absolutely necessary.
But Hanja is a large topic, and it can take years to learn how to read and write all of the characters. It doesn't need to be this difficult to use Hanja to benefit your Korean. Even just a few characters can help, and you can always add more later as you go.
It'd be impossible to cover all of the necessary Hanja to learn in just a few hours, but this should be a decent introduction to the concepts you'll need.