http://msdn.microsoft.com/en-us/library/ms187928.aspx[
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Never had a reason to use SQL's "convert", but apparently it is forcing the dates into a common format (varchar) with a length of 10, "04/15/2014". This ensures that the where statement is comparing identically formatted dates.
it's selecting records that were updated on a particular day determined by the GETDATE() function and matching the dates as a 10-character string.