Both processes and threads are used to achieve parallelism in programs. However, there are several differences between the two.
A process is a running program that has its own memory space, system resources, and state. Each process is a separate instance of a program, and multiple processes can be run simultaneously. For example, when you run multiple applications on your computer, each application is a separate process. Each process has a unique process identifier (PID), which is used by the operating system to manage and communicate with the process.
On the other hand, a thread is a subset of a process. A thread is a lightweight execution unit that shares the memory space and system resources of the parent process. A process can have multiple threads, and each thread executes concurrently. Threads share the same memory space as the parent process, which allows them to share data and communicate more efficiently. For example, when you open a web browser and load a webpage, the browser creates multiple threads to handle tasks such as rendering the webpage, handling user input, and communicating with the network.
The major difference between processes and threads is that processes are independent of each other, while threads share the same memory space and resources. This means that processes cannot access each other's memory space directly, while threads can access any part of the parent process's memory space.
Another difference is that creating a new process is more resource-intensive than creating a new thread. This is because a new process requires a new memory space and a copy of the parent process's resources, while a new thread only requires a new stack space and a thread control block (TCB) in the parent process's memory.
To summarize, processes and threads both provide a way to achieve parallelism in programs, but they differ in their independence and resource usage. Processes are independent and have their own memory space, while threads share the same memory space and resources of the parent process.
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