If you update the text for a control caption or text property, using the
Repaint method causes the form to refresh the control contents to the
screen. This is especially handy when you've built things like a progress
bar and are doing lots of automated processing. The normal thing to happen
in this instance is that form repaints are done as opportunity presents.
Using the repaint  method means that you sacrifice a little speed to force
the graphics engine to update the appearance of the form and update the
visible contents of the form's child controls as seen by your customer.