How To Access Variables From Another Script In Unity

What is the easy and Best way to access variables in another script. I try

GameObject.FindGameObjectWithTag(“Player”).GetComponent();

But I Think work code this player must in the scene.

Sorry for my bad English,

Referencing variables, fields, methods (anything non-static) in other script instances:

https://discussions.unity.com/t/833085/2

https://discussions.unity.com/t/839310