This is the 6383rd most frequent Catalan word.
of
The Catalan word "of" does not exist. You may mean "of" in English or a different Catalan word like "ofici" (trade/occupation).
Here, 'de' specifies the event or occasion tied to the noun.
El sopar de Nadal és especial.
The Christmas dinner is special.
In this case, 'de' denotes relationship or association between terms.
El color de la samarreta és blau.
The color of the shirt is blue.
Here, 'de' is used to indicate possession or source.