line by line meaning of this query

Question

CREATE PROCEDURE GetCustomersPageWise

      @PageIndex INT = 1

      ,@PageSize INT = 10

      ,@RecordCount INT OUTPUT

AS

BEGIN

      SET NOCOUNT ON;

      SELECT ROW_NUMBER() OVER

      (

            ORDER BY [CustomerID] ASC

      )AS RowNumber

      ,[CustomerID]

      ,[CompanyName]

      ,[ContactName]

     INTO #Results

      FROM [Customers]

     

      SELECT @RecordCount = COUNT(*)

      FROM #Results

           

      SELECT * FROM #Results

      WHERE RowNumber BETWEEN(@PageIndex -1) * @PageSize + 1 AND(((@PageIndex -1) * @PageSize + 1) + @PageSize) - 1

     

      DROP TABLE #Results

 

 

 this query used by someone for paging in reapter i want to know what are the meaning of this query