use Module or Class

I am using ASP.NET 2.0
I am little bit confuse to use Class / Module
 
I get a generic list of customers and store it in a session variable, for creating a generic list I use class. I use this function to populate customer grid.
 
Imports Microsoft.VisualBasic
Imports System.Collections.Generic
Imports MyCreatingDLL

Public Class GetData
 
Private ObjField1 As Object
Private ObjField2 As Object
 
   Public Property Field1() As Object
        Get
            Field1 = ObjField1
        End Get
        Set(ByVal value)
            ObjField1 = value
      &nbs ...