• A system call is a method that allows a process to communicate with the operating system. It's the method by which a computer programme requests a service from the operating system's kernel.
• A system is used to create a fork, which is a new or duplicate process.
• The duplication process includes all data in the file description as well as the common registers. The original process is referred to as the parent process, while the copy is referred to as the child process.
• The fork call returns a value in the child that is zero and equal to the PID (Process Identifier) of the child in the parent. Exit, for example, is a system call that asks for services to terminate a process.
• Execution of exec is required when loading programmes or replacing the original image with a duplicate. Pid would assist in distinguishing between child and parent processes.

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