Row numbering in TSQL 2005 - SQL

New to SQL Server 2005 is ROW_NUMBER function.

SELECT
JobLog.JobLogID,
Establishment.EstablishmentName,
JobSubType.JobSubTypeDescription,
JobLog.JobLogSignOffTimeStamp,
ROW_NUMBER() OVER(ORDER BY EstablishmentName ) AS rownumNonDeterministic,
ROW_NUMBER() OVER(ORDER BY EstablishmentName,JobLog.JobLogSignOffTimeStamp ) AS rownumDeterministic,
ROW_NUMBER() OVER(PARTITION BY EstablishmentName ORDER BY EstablishmentName,JobLog.JobLogSignOffTimeStamp ) AS rownumPartitioning
FROM JobLog
INNER JOIN
Establishment ON JobLog.JobLog_EstablishmentID = Establishment.EstablishmentID  
INNER JOIN
JobSubType ON JobLog.JobLog_JobSubTypeID = JobSubType.JobSubTypeID
WHERE JobLog.JobLogSignOff = '1'
ORDER BY EstablishmentName,JobLog.JobLogSignOffTimeStamp