Running more than a few threads is like running several different programs at the same time as, but with the following profits:
• Multiple threads inside a process share the same data space with the main thread and can consequently share information or communicate with each other more effortlessly than if they were separate processes.
• Threads sometimes described light-weight processes and they do not require much memory overhead; they care cheaper than processes.
A thread has a beginning, an execution sequence and a conclusion. It has an instruction pointer that maintains track of where within its context it is at present running.
It can be pre-empted (interrupted)
It can temporarily be put on hold (also known as sleeping) while additional threads are running - this is called yielding.