Shortest Job First(S.J.F): Shortest Job First (SJF) is a CPU scheduling algorithm that selects the process with the shortest burst time or execution time to be executed first. The basic idea behind this algorithm is that shorter jobs are likely to finish before longer ones, resulting in faster overall processing and turnaround times.

There are two types of SJF algorithms:

Non-preemptive SJF: In this algorithm, once a process is selected for execution, it continues until it finishes, and the CPU is released.
Preemptive SJF: In this algorithm, if a new process with a shorter burst time arrives, it interrupts the current executing process and takes over the CPU. The interrupted process is put back into the ready queue to wait for its next turn.

One of the major advantages of SJF is that it has a minimal average waiting time, which means that processes with shorter burst times will be executed sooner, resulting in less time spent waiting in the ready queue. However, SJF can cause starvation for longer processes if shorter processes keep arriving, and it is difficult to estimate the exact burst time for each process.
To implement the SJF algorithm, the burst time for each process needs to be known beforehand. This can be achieved by using historical data, such as the average burst time for a specific process or by estimating the burst time based on the type of process. Additionally, the SJF algorithm can be used in conjunction with other scheduling algorithms, such as Round Robin or Priority Scheduling, to achieve better results.