Why should I use SerializeField?

Question

I have just started to learn C# and Unity, and there is one thing that I can not get used to:

Why and when should I use [SerializeField]?

Is it

Answer 1

The [SerializeField] attribute is used to mark non-public fields as serializable: so that Unity can save and load those values (all public fields are serialized by default) even though they are not public.

That's all it does. You use it when you want that.