AutoResetEvent Notifies a waiting thread that an event has occurred. This class cannot be inherited.

 ManualResetEvent Notifies one or more waiting threads that an event has occurred. This class cannot be inherited.

 Thread Creates and controls a thread, sets its priority, and gets its status.

 ThreadAbortException The exception that is thrown when a call is made to the Abort method. This class cannot be inherited.

 Timer Provides a mechanism for executing a method on a thread pool thread at specified intervals. This class cannot be inherited.

 ThreadPriority Specifies the scheduling priority of a Thread.

 ThreadState Specifies the execution states of a Thread.

 Interlocked Provides atomic operations for variables that are shared by multiple threads.

 Monitor Provides a mechanism that synchronizes access to objects.

 Timeout Contains constants that specify infinite time-out intervals. This class cannot be inherited.

 WaitHandle Encapsulates operating system–specific objects that wait for exclusive access to shared resources.