First Come First Served (FCFS) is an algorithm for the order in which jobs are allocated and processes are handled. The FCFS method is used in processor scheduling, as well as in the storage of data and for controlling the read/write heads ofhard disks
In the FCFS algorithm, jobs are allocated and processed in the order in which they are received. Jobs that are received first are also serviced first. In terms ofcontrolling the read/write heads of hard disk drives, this means that data can be positioned anywhere on the disk without any major loss of time.
Other algorithms for allocating processor power include Shortest Job First (SJF), Round Robin (RR), Fixed External Priorities (FEP), and Earliest Deadline First (EDF). In hard disk drive control, an alternative method is Shortest Seek First (SSF) with the shortest deflection of the access arm.