What is the function of the KeyPreview property of a form? (set shortcut keys and hooks)

If you set the KeyPreview property of the form to true, the form will take precedence over the control of the keyboard event to get the activation right. For example, if the form Form1 and its text box Text1 are ready to respond to the KeyPress event, the following code will first activate the KeyPress event of the form:

Private Sub Form_Load ()
    Me.keypreview = True
End Sub

Private Sub form_keypress (KeyAscii as Integer)
    MsgBox "This is the KeyPress event of the form"
End Sub

Private Sub text1_keypress (KeyAscii as Integer)
    MsgBox "This is the KeyPress event of the text box"
End Sub

What is the function of the KeyPreview property of a form? (set shortcut keys and hooks)