means the process is being created, Ready means that task or process is waiting to be allotted to any processor, Run means instructions are being executed Wait means that process is waiting for some other event to occur Terminate means the program or process execution has finished. There thread is a part of the process. Where the process has long time for termination and also execution . Depending on the operating system a process can be made up of multiple threads of execution where the instructions are executed concurrently.