Threads in Operating System | What is a Process? | Types of Threads | Examples of Threads

Thread refers to a single sequential activity being executed within a process.
In an operating system that supports multithreading, the process can consist of many threads.
Processes are basically the programs that are dispatched from the ready state and are scheduled in the CPU for execution.
Inside a process, the execution of single sequential activity (lightweight process)is known as a thread.
A thread is a lightweight process running within a larger process or within an operating system.
The thread has a program counter that keeps track of which instruction to execute next.
It has registers that hold current working variables.
It has a stack, which contains the execution history.
Threads can create child threads.
In multi-threaded systems, threads allow multiple processes to run simultaneously, greatly speeding up a process' operation and preventing processes from blocking each other's execution
User Level Thread: User-level threads are implemented and managed by the user and the kernel is not aware of it.
User-level threads are implemented using user-level libraries and the OS does not recognize these threads.
User-level thread is faster to create and manage compared to kernel-level thread.
2. Kernel level Thread: Kernel level threads are implemented and managed by the OS
Kernel level threads are implemented using system calls and Kernel level threads are recognized by the OS.
Kernel-level threads are slower to create and manage compared to user-level threads.