The particle 보다 is used to make a comparative sentence. This particle is attached to a noun that is being compared, and it is translated as “more than” or “rather than.” Consider the following example:

언니(의) 방이 제 방보다 커요.

“(My) older sister’s room is bigger than my room.”

Notice that “older sister’s room” is the noun that is being compared to “my room.”