1.A process can have many threads but a thread cant have many process
2.Creation of new process needs new resources and Address space but
the thread can be created in the same address space of the process
3.Threads can directly communicate with other threads of its process;
processes must use inter-process communication to communicate with sibling processes
4.Operating system is aware of process it can see the processes. But operating system is NOT aware of thread do not see them.