This is a stupid question. There are a ton of different wait types, as documented in Books On Line and in a well written Word Doc white paper by Microsoft about SQL Server Waits and Queues in SQL Server 2005 (it applies to all versions 2000 and up). Anyway, I think it's best to ask "Tell me about how you interpret wait types when trouble shooting and when monitoring SQL Server databases." Yes, some wait types are more common than others, but its the interpretation of them that hold value. The answer to this psuedo question is: wait types show what a sql server process is currently waiting on to complete, for how long the current transaction is waiting and what the type wait time is for the connection. See wait types is perfectly normal, however it is the time between waits that is important. For example, if you see CXPACKET wait type, showing that sql server is currently resolving a query with a parallel execution place, that's fine, it's the TIME per execution that matters. So see 10ms across the spid list in activity monitor is a lot different (better) than seeing 452123ms. What is DUMB question.......