What are some common SQL Server wait types?

Examples include PAGEIOLATCH waits associated with waiting for database pages to be read from storage, LCK_M_* waits associated with lock blocking, RESOURCE_SEMAPHORE associated with query memory grant waits, WRITELOG associated with transaction-log flush latency, and SOS_SCHEDULER_YIELD associated with CPU scheduler pressure or CPU-intensive execution.

Parallel-query waits include CXPACKET and CXCONSUMER, whose interpretation depends on SQL Server version and workload.

No wait type should be treated as automatically bad; identify the queries and resource conditions producing it.