First Come First Serve

First Come First Serve (FCFS) is a scheduling algorithm used in computer science to determine the order in which tasks or processes are executed. It follows the principle that the task or process which arrives first will be executed first.

Here is a step-by-step explanation of how the FCFS algorithm works:

1. Start by initializing a queue to hold the tasks or processes. The queue is empty initially.

2. As tasks or processes arrive, they are added to the end of the queue. The order in which they arrive is preserved.

3. When a task or process is completed or finishes its execution, it is removed from the front of the queue.

4. The next task or process in the queue is then selected for execution, as it is the one that arrived first.

5. This process continues until all the tasks or processes have been executed, and the queue becomes empty.

6. The FCFS algorithm does not consider the length or complexity of the tasks or processes. It simply executes them in the order they arrived.

7. One advantage of FCFS is its simplicity and fairness. It ensures that every task or process gets a chance to execute, without any bias or priority.

8. However, FCFS can suffer from a drawback known as the "convoy effect." If a long-running task or process arrives first, it can hold up subsequent tasks or processes, leading to a slower overall execution time.

9. FCFS is commonly used in situations where fairness is more important than efficiency, such as in batch processing or non-interactive systems.

10. Overall, the FCFS algorithm is a straightforward approach that serves tasks or processes in the order they arrive, making it a popular choice in certain scenarios.