Profiler records events that occur on the server. The events range from SQL queries executed to locks acquired, to logins/logouts, to deprecations, deadlock and a whole lot more.
Performance dashboard is a front end on top of some of the 2005 DMVs.
Which you use depends what you're trying to do.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
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