الفرق بين ثلاث مصطلحات في انظمة التشغيل

1. Spool helps in matching different devices with their speeds. eg - Printer. Many
computing devices with different configuration are connected to a common printer. The jobs
provided to the printer are not only dependent on the printer printing speed, but also the
paper that is available. So when I provide a job (normally it’s called so) to it, it needs to have
finished its previous jobs (maybe given by other networked devices). Until then my
computing device won't stop functioning. Still my processor is available for me.
Buffer mainly helps us in keeping our processor occupied at all times. We bring
relevant information ready to be consumed and provide us with results. Here nothing gets
stored after processing.
Cache mainly helps us in re-using data that is there. Frequently used things are
in L1 and remain in L1 until some other thing's usage becomes more frequent than this
existing and there is less space in L1. If so its moved to a bigger space L2. Same is the case
for moving things from L2 to L3. These are the types of caches present which are
differentiated according to their sizes. Sizes are as L1 < L2 < L3.