This is the 1964th most frequent Turkish word.
okulların
"Of the schools" or "schools'"
In this sentence, 'okulların' is used in possessive genitive form referring to 'schools', indicating 'of schools'. It shows the relationship between schools and the surrounding area.
Okulların çevresinde çocuklar oynuyordu.
Children were playing around the schools.
Here, 'okulların' again functions as possessive genitive meaning 'of schools', referring to their organization or system.
Okulların düzeni öğrenimi etkiler.
The organization of schools affects learning.
In this sentence, 'okulların' is used possessively relating to 'the new project', showing that the project is being initiated by the schools.