A little but it’s “industry standard oAuth” so it roughly follows the oAuth specific used by many sites/services to create links between Client’s and Users.
What are you actually trying to do.
I outlined three different authentication methods in my first reply and the one to use depends on what you are doing.
If you have the username or ID then you can use an App Access Token to load publc data
If you want to get information about the logged in user then you use token you got from the authentication loop.
The simplest is this implict auth example, which just needs a WebBrowser and Javascript. No java involved
https://barrycarlyon.github.io/twitch_misc/authentication/implicit_auth/
However this authentication method is probably not suited to what you want to actually do.