I think the '의' you're probably referring to is the possessive particle. It's like "of" or "'s" in English. The usage is Noun 1의 Noun 2. For example, "mom's car" would be "엄마의 차" in Korean.

의=The

1. David's pan 데이빗의 펜. David's car 데이빗의 자동차. 2. work of David. 데이빗의 일. cat of David. 데이빗의 고양이.

* 예를 들어 주세요. give me a example.