This is the 600th most frequent Azerbaijani word.
rayonun
"The district's" or "of the district".
Here, "rayonun" is used in the form of a possessive noun to indicate 'of this district.'
Bu rayonun təbiəti çox gözəldir.
The nature of this district is very beautiful.
In this sentence, "rayonun" specifies the residents belonging to the district.
Rayonun sakinləri bayram hazırlıqlarındadırlar.
The residents of the district are preparing for the holiday.
Here, "rayonun" is possessive, linked to 'development' to indicate the development of the district.