Chat bot Telegram::Bot::Client.run?

Question

ruby

in the bot for the telegram on ruby ​​https://github.com/atipugin/telegram-bot-ruby there is a line
Telegram::Bot::Client.run(token)
then it runs the code (there are no questions about this)
What exactly is Telegram: :Bot::Client.run runs? what third party gem does it use? I understand that the longpoll method is used?
How to implement the same for VK chat?