title: What are the event arguments "sender" and "e"
body: <p>I'm struggling to understand these arguments.<br>
  They are automatically generated and I don't need to give them much thought but if I want to call one of these events from some other part of the form then I need to supply these arguments with values - not easy as I'm still unsure what they mean.  </p>
  
  <p>Here is the event I'd like to <code>Call</code>:</p>
  
  <pre><code>Private Sub stringButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles stringButton.Click
      Dim outString As String
      Select Case stringTextBox.Text
          Case ""
              outString = "You entered an empty string"
          Case "10"
              outString = "10"
          Case Else
              outString = "Your string is not covered by the cases"
      End Select
      strResultTextBox.Text = outString
  End Sub
  </code></pre>
  
  <p>Here is the calling method:</p>
  
  <pre><code>Private Sub stringTextBox_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles stringTextBox.KeyDown
      If e.KeyCode = Keys.Enter Then
          Call stringButton_Click(Me, Me) '&lt;&lt;(Me,Me) is my incorrect attempt
      End If
  End Sub
  </code></pre>
  
  <p>What arguments should I use and why?</p>