Kong is a powerful proxy built on nginx. By taking a request and passing it to an upstream server and then returning the result to the client Kong can perform his magic. To know which requests go to which service Kong looks for a Host header to match against. There's a few other ways Kong can match requests to services but for now that's the most basic route. Pun intended.
Assuming everything has been installed and setup, such as dependencies and config files which can be found in the docs, it's time to turn Kong on. The first time Kong runs you'll see some Kong config values and initial migrations to the datastore.
kong start