Well, scene redirection is simply opening another scene in Unity programmatically after something happened, for example after login, after logout, etc.
I made this video to answer some questions about how to show a text message on our Unity UI programmatically and how to redirect a user to another scene, for example after a successful login attempt, to let's say a dashboard page.
Previously I've made some tutorial videos how to create a login and register feature for your Unity games with PHP and MySQL backend here • Unity & PHP Login Logout and Register... , and these questions came from them that watched those videos.
Hope this helps.