Loop

[Muhammad Nauman]

i have taken this code from http://channel9.msdn.com/coding4fun/articles/Basic-Chat-Using-ASP-NET-AJAX.
Global.asax:

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)

        Dim chatters As List(Of Chatter) = New List(Of Chatter)
        chatters.Add(New Chatter(New Guid("CD863C27-2CEE-45fd-A2E0-A69E62B816B9"), "Me"))
        chatters.Add(New Chatter(Guid.NewGuid, "Juan"))
        chatters.Add(New Chatter(Guid.NewGuid, "Joe"))
        Application.Add("Chatters", chatters)
        
       Dim chats As List(Of Chat) = New List(Of Chat)
        chats.Add(New Chat)
        Application.Add("Chats", chats)
       
         For Each c As KeyValuePair(Of Guid, Chatter) In Chatter.ActiveChatters
  c.Value.Join(Chat.ActiveChats(0))
  Next

I am unable to understand last 3 lines that are bold and underlined. Please what is hppening here. Chatter and Chat are two classes defined in App_Code folder.
Alo what it means? Is there any sight that contains all possible ways to declare and initilaze variables and data structure:
Dim chatters As List(Of Chatter) = New List(Of Chatter)
please help me.