Basic Noob Question About C#

I'm curious as to why the definition of a variable needs to be stated twice. For instance:

public GUISkin skin;

//then:

void OnGUI()
{
GUISkin = skin
}

//or:

public scoreLevel manager;

//then:

void Start()
{
manager = manager.GetComponent<scoreLevel>();
}

 

Or maybe these aren't called variables.

 

It doesn't and in fact it isn't being defined twice.

Here you are defining the variables.

Here you are setting the values they contain (technically the GUISkin one is a bit odd - I'm fairly certain that's supposed to be GUI.skin).

Technically they're variables but officially they're known as fields because they belong to the class (or struct) definition.

https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/fields

 

Yes, it's GUI.skin. I copied and pasted it. I don't know how it was changed because it's that way in the code. Weird. Thanks for the reply. I don't know enough about code yet to fully understand your answer but you've given me something that may click into place later.