What de the differences between process and thread? Explain and give figures. (SP) (LO8, LO4)

Process and thread are both fundamental concepts in operating systems and computer science, but they have distinct differences:<br /><br />1. **Definition**:<br /> - **Process**: A process is an instance of a computer program that is being executed. It contains the program code, a current activity, and a unique process identifier (PID). Each process runs in its own memory space.<br /> - **Thread**: A thread is a smaller unit of execution within a process. It can execute concurrently with other threads within the same process. Threads share the same memory space and resources as the process.<br /><br />2. **Memory**:<br /> - **Process**: Each process has its own memory space, which is isolated from other processes. This isolation ensures that one process does not interfere with another.<br /> - **Thread**: Threads within the same process share the same memory space. This sharing allows for efficient communication and resource sharing between threads.<br /><br />3. **Creation and Management**:<br /> - **Process**: Creating a new process is a heavier operation because it involves allocating a new memory space and initializing a new execution context.<br /> - **Thread**: Creating a new thread is lighter because it reuses the existing memory space and execution context of the parent process.<br /><br />4. **Communication**:<br /> - **Process**: Communication between processes typically requires inter-process communication (IPC) mechanisms such as pipes, sockets, or message queues.<br /> - **Thread**: Communication between threads is more straightforward since they share the same memory space. However, synchronization mechanisms like semaphores or monitors are needed to prevent data races and ensure thread safety.<br /><br />5. **Resource Allocation**:<br /> - **Process**: Each process has its own set of resources, such as CPU time, memory, and I/O devices.<br /> - **Thread**: Threads within the same process share the same resources, which can lead to more efficient use of system resources but also requires careful management to avoid resource starvation.<br /><br />In summary, while both processes and threads are units of execution, processes are independent and isolated, whereas threads are lightweight and share resources within the same process.