Wait statistics provide important information for monitoring and improving SQL Server performance. They indicate where the server is spending time waiting on resources and which resources are causing frequent or long waits. Key wait statistics are available in dynamic management views like sys.dm_os_wait_stats and sys.dm_db_wait_stats. Some waits like PAGEIOLATCH_IO_COMPLETION are more important to focus on than others like CXPACKET. Wait statistics can help identify issues related to the system, queries, or database structure. Extended events and other views also provide related wait information down to the query level.