This is the 8768th most frequent Russian word.
пограничники
Border guards.
In this sentence, 'пограничники' refers to border guards as personnel responsible for securing a country's borders.
Пограничники остановили нас на границе для проверки документов.
The border guards stopped us at the border to check our documents.
Here, 'пограничников' is used in the genitive case to describe the group of people performing the task.
Важной задачей пограничников является предотвращение незаконного пересечения границы.
An important task of border guards is preventing illegal border crossings.
In this instance, 'пограничники' emphasizes the profession or job title of the people involved.