A process is an independent program in execution with its own memory space, resources, and system allocation. A thread is a smaller execution unit that exists within a process and shares the process's memory and resources with other threads. Processes provide isolation and stability, while threads enable efficient multitasking and parallel execution within the same application.
Key Points:
• A process has its own memory space, whereas threads within a process share the same memory. • Creating a process is more resource-intensive than creating a thread. • Communication between processes is slower and requires IPC mechanisms, while threads communicate through shared memory. • A failure in one process usually does not affect other processes, but an issue in one thread can impact the entire process. • Threads are commonly used to improve application responsiveness and performance.
Example:
When you open a web browser, it runs as a process. Inside that browser process, multiple threads may handle tasks such as rendering web pages, downloading files, playing media, and responding to user actions simultaneously.
Key Differences:
•Process Independent execution unit Has separate memory space More secure and isolated Slower context switching
•Thread Lightweight execution unit Shares memory with other threads Faster communication Faster context switching
Interview Tip:
A concise interview answer is: "A process is an independent program execution unit with its own memory and resources, while a thread is a lightweight execution unit within a process that shares the same memory and resources. Processes provide isolation, whereas threads improve concurrency and performance."