Does Unity automatically scale your project for different resolutions?

I'm new to Unity, and I just wanted to know if I had to figure out how to code my game for different resolutions or if it would just scale with the size of the scene. For example: Would it change the scale of everything change if I changed aspect ratio from 16:9 -> 16:10? And how do I actually know what aspect resolution the project is in / how would I set it to a certain aspect ratio and resolution.

 

For different resolutions and aspect ratios, you can preview what they will look like using the game view window. There's a drop-down menu that shows you several different settings, or you can add your own.

https://docs.unity3d.com/Manual/GameView.html

On that manual page, scroll down to where it says
Game view Control Bar
and you'll see the drop-down I'm talking about.