Can you explain in brief how can we implement threading ?

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
Dim pthread1 As New Thread(AddressOf Thread1)
Dim pthread2 As New Thread(AddressOf Thread2)
pthread1.Start()
pthread2.Start()
End Sub
Public Sub Thread1()
Dim pintcount As Integer
Dim pstr As String
pstr = “This is first thread”
Do Until pintcount > 5
lstThreadDisplay.Items.Add(pstr)
pintcount = pintcount + 1
Loop
End Sub
Public Sub Thread2()
Dim pintcount As Integer
Dim pstr As String
pstr = “This is second thread”
Do Until pintcount > 5
lstThreadDisplay.Items.Add(pstr)
pintcount = pintcount + 1
Loop
End Sub

Above is a sample code which shows simple sample code for threading. Above sample code can be found in “Threading” folder in CD provided. Above sample has two methods “Thread1()” and “Thread2()” which are started in multi-threaded mode in Form load event of the sample.
Note :- If you run the sample you will see that sometimes the first thread runs first and then the second thread.