How does visual know what form I want?

Question

So I have the folowing code for a form.

Public Class tab
     Public personas, formaciones, avisos, cursos As List(Of Object)
     [Lots of Code]
End class

On another form I want the formaciones List, so I can just:

ListBox1.DataSource = tab.formaciones

And it works, perfectly.

But.. How?

tab is a class, not an instance of it, but vb is able to understand that I want the instance of that class.

What happen if there are mor than one tab open? How does it work internally?

You could [read this](http://stackoverflow.com/questions/4698538/why-is-there-a-default-instance-of-every-form-in-vb-net-but-not-in-c). VB create an instance of each form for you, that's why it works. But you would have to specify which instance you want if you have multiple forms. — the_lotus, Jun 29 '16 at 11:49
@ThorstenDittmar actually, vb does create instance "on the fly" for each forms. — the_lotus, Jun 29 '16 at 11:51
@the_lotus One more reason to stay away from VB as far as possible and learn a proper language in the first place... Anyway: In this example, `tab` is not a form? — Thorsten Dittmar, Jun 29 '16 at 11:51
@ThorstenDittmar, yes poor naming. Even more when you consider that `tab` is my main form. So yes, it have an instance. But how does visual know that Im referring to that instance when I'm just using the class name? — Aimnox, Jun 29 '16 at 11:52
@ThorstenDittmar I prefer C#, but work inforces vb use so... — Aimnox, Jun 29 '16 at 11:53
@the_lotus And if I had multiple instances and I wrote the same line, which one would it access? — Aimnox, Jun 29 '16 at 11:54
@Aimnox an instance with the same name as the class is generated. If you had multiple instance, you would have a variable for each so it would all depend on which variable you chose to use. — the_lotus, Jun 29 '16 at 12:03
@the_lotus but it doesn't generate a new instance, it takes the existing one — Aimnox, Jun 29 '16 at 12:50