Fluid layout, scaling in unity?

Question

C++ / C#

Hello everyone, I didn’t quite understand how to deal with different screens, Google, YouTube, the community forum did not give an answer.
Please tell me, is there a player, how to scale it based on the screen size?
You can, of course, in onStart or Awake, transform.scale * by some coefficient depending on the width of the screen, but it seems to be a crutch, the feeling that everything should be easier)
Please tell me how this is implemented?