This is the 3839th most frequent Russian word.
vk
"VK" is a Russian social media platform similar to Facebook.
In this sentence, 'ВКонтакте' is used as the name of a social network, VKontakte, known colloquially as 'VK'.
Я провожу много времени на сайте ВКонтакте каждый день.
I spend a lot of time on the VKontakte site every day.
Here, 'VK' is the abbreviation commonly used for the social network VKontakte.
У меня есть аккаунт на VK.
I have an account on VK.
In this case, 'VK' refers again to VKontakte but highlights its use as a platform for communication.